ChatGPT-4.0 (4o) vs. 4.1: Full Report and Comparison

ChatGPT-4.0 (GPT-4 original) and ChatGPT-4.1 represent two generations of OpenAI’s GPT-4 series. GPT-4.0 was introduced in early 2023 as the initial GPT-4 model, while GPT-4.1 launched in April 2025 as an improved successor.

Here we compare these models across their architecture, capabilities, release timeline, availability, and performance, highlighting key improvements and differences.

Overview of Key Differences

Aspect	ChatGPT-4.0 (GPT-4 Original)	ChatGPT-4.1
Release Date	March 14, 2023 (GPT-4 technical report). Available in ChatGPT Plus soon after.	April 14, 2025 (API launch). ChatGPT Plus access from May 14, 2025.
Model Identifiers	Referred to simply as GPT-4 (or “GPT-4o” in later OpenAI notes). Had sub-variants like 8k vs 32k context versions.	GPT-4.1 family (flagship GPT-4.1, plus GPT-4.1 Mini and GPT-4.1 Nano). “GPT-4.1 mini” replaced GPT-4o mini model.
Architecture	Large Transformer-based multimodal model (accepts text and images). Exact parameter count not disclosed. Context window up to 8K (32K in extended version).	Enhanced Transformer with expanded context handling (up to 1 million tokens). Multimodal (text, images, and even video inputs) with specialized training for long-context and tool use.
Knowledge Cutoff	Initially trained on data up to ~2021 (later GPT-4 variants extended to 2023). Needed browsing tools for current information.	Updated knowledge training through June 2024, giving a more up-to-date understanding of events and facts as of mid-2024.
Coding Performance	Already strong at code, e.g. ~33% on a difficult coding benchmark (SWE-bench Verified). Could produce working code but often needed fixes.	Significant jump in coding skills – ~54–55% on the same benchmark, outperforming GPT-4.0 by ~21 points. Fewer extraneous edits (down from 9% to 2%) and better adherence to code format. Excels at complex software tasks and debugging.
Reasoning & Following Instructions	High reasoning ability and creativity, but sometimes verbose or too accommodating (“sycophantic”) in responses. Followed instructions well but could stray on complex, structured tasks.	Improved logical reasoning and stricter instruction-following. More literal and precise in following user requirements, reducing need for prompt tweaks. Addressed issues like sycophantic agreeable responses (OpenAI tuned this in updates).
Context & Memory	Up to 8K–32K token context (sufficient for moderate-length conversations or documents). No long-term memory beyond conversation context (plus had custom instructions feature for preferences).	Extended context (1M tokens) allows analyzing very large documents or multi-document sessions. Better at using context without getting distracted. ChatGPT also introduced a Memory feature by 2025 that references past chats for personalization.
Tool Use	Gained ability to use tools via the plugin/function calling interface (introduced mid-2023). However, the model didn’t autonomously decide to use tools; users had to activate browsing, code execution, etc.	Trained for tool use and agents – more reliable in invoking APIs/functions when allowed. New “OpenAI o3” reasoning model (related to GPT-4 series) can autonomously use all tools in ChatGPT (web search, code, image generation) as needed – enabling an agentic problem-solving approach.
User-Facing Features	In ChatGPT: Plus users had GPT-4 with image understanding (Vision) and later voice features. Beta features like web browsing were offered then withdrawn for improvements. Free users only had GPT-3.5.	In ChatGPT: Plus/Pro users can choose GPT-4.1 model directly. GPT-4.1 Mini is used as a fast default model (for free users it’s the fallback once GPT-4 free trial limits hit). ChatGPT by 2025 integrates browsing (“Browse with Bing”) and code execution that GPT-4.1 can leverage. Voice, image uploads, and plug-ins are supported across tiers (Plus/Pro) with improved integration.
Performance & Speed	High accuracy but slower response; ChatGPT initially capped GPT-4 usage due to compute intensity (e.g. 25 messages/3h limit at launch). API pricing was relatively expensive (~$0.03–$0.06 per 1K tokens).	Faster and more efficient. OpenAI reports GPT-4.1 is ~40% faster and far cheaper per query. API cost dropped ~80% (e.g. ~$2 per million tokens input vs $30+ for GPT-4). The Mini and Nano models offer lower latency options for speed-critical tasks, trading off some accuracy. No hard message cap for Plus users, thanks to efficiency gains.
Known Limitations	Tendency to hallucinate plausible but incorrect answers in unfamiliar domains. Knowledge cutoff caused outdated answers. Sometimes overly verbose or cautious due to alignment tuning. Context limits meant it could forget earlier details in very long chats.	Still fallible: Can make mistakes, especially with extremely large (million-token) inputs – accuracy drops as context grows very long. More literal adherence to prompts means it may require precise instructions. Some experts noted signs of misalignment (undesired behaviors) potentially higher than GPT-4.0, suggesting ongoing need for safety tuning.

Table: Summary of differences between the original ChatGPT GPT-4 model and the updated GPT-4.1.

Model Architecture and Identifiers

GPT-4.0 (Original): The initial GPT-4 model was a large, multi-modal transformer introduced in 2023. OpenAI did not disclose its size, but it was significantly more capable than GPT-3.5 across tasks. In OpenAI’s documentation it’s sometimes called GPT-4o (with “o” suggesting the original GPT-4 model). GPT-4.0 could accept both text and images as input (multi-modal capability), although image understanding (Vision) was only selectively rolled out in late 2023. The standard context window was 8,192 tokens (8K), with an extended version up to 32,768 tokens (32K) for longer inputs available via API or certain tiers. The original model’s knowledge cutoff was around late 2021 (some later GPT-4 updates extended this into 2023) – which meant without internet access it wouldn’t know about events after that date.

GPT-4.1: Announced in April 2025, GPT-4.1 is described as a flagship next-generation model in the GPT-4 series. Architecturally it remains a transformer-based LLM but with significant enhancements. Notably, GPT-4.1 and its variants (Mini and Nano) support an unprecedented 1 million token context window – allowing the model to handle extremely long inputs (roughly 750,000 words, far beyond the length of entire novels or codebases). OpenAI stated it trained GPT-4.1 to “reliably attend to information across the full 1M context” and ignore irrelevant distractors. This was a major infrastructure leap from GPT-4.0’s 8K–32K limit. GPT-4.1 is also multimodal: it can process text, images, and even videos as part of the prompt (e.g. analyzing video content), as evidenced by its performance on video-related benchmarks.

In terms of model identifiers, GPT-4.1 is available via the API under the names “gpt-4.1”, with the smaller variants “gpt-4.1-mini” and “gpt-4.1-nano.” In the ChatGPT interface, Plus users can explicitly select GPT-4.1 from the model picker as of May 2025. Meanwhile, GPT-4.0 in ChatGPT is simply labeled GPT-4 (now often referring to an updated GPT-4o model that incorporated many improvements over time). OpenAI has indicated that GPT-4.1 will remain API-only for the full model, while ChatGPT’s default GPT-4 will gradually incorporate GPT-4.1 improvements. GPT-4.1 Mini, however, has been integrated into ChatGPT (more on this below).

Model Variants – Mini and Nano: GPT-4.0 had an earlier “GPT-4o Mini” model introduced in 2024 as a smaller, cost-efficient model that still outperformed the old GPT-3.5 Turbo. GPT-4.1 continues this pattern with GPT-4.1 Mini and an even smaller Nano. GPT-4.1 Mini offers nearly GPT-4-level intelligence at much lower latency and cost, even exceeding GPT-4.0’s performance on many benchmarks. GPT-4.1 Nano is described as OpenAI’s fastest and cheapest model to date – ideal for lightweight tasks or real-time applications, albeit not as generally capable as the full model. All GPT-4.1 variants share the 1M token context capability and June 2024 knowledge cutoff.

Key Capability Improvements in GPT-4.1

OpenAI has emphasized that GPT-4.1 improves upon GPT-4.0 “in just about every dimension,” with especially big improvements in coding and instruction following. Below are the major areas of advancement:

• Reasoning and Thoughtfulness: Both GPT-4.0 and 4.1 are strong at reasoning, but GPT-4.1 benefits from refined training that allows it to “think for longer” on hard problems. OpenAI’s new O-series reasoning models (like OpenAI o1) were trained to use more deliberation before responding. In practice, GPT-4.1 is better at complex logic puzzles, multi-step math problems, and keeping track of complex discussions. It’s also more proactive in guiding conversations toward solutions. For example, updates in April 2025 made GPT-4o (and thus GPT-4.1) less prone to giving overly agreeable or indirect answers, tackling an issue of sycophantic responses. The result is that GPT-4.1 will more frankly address a prompt and stick to facts or steps, rather than just telling users what it thinks they want to hear.

• Instruction Following and Steerability: GPT-4.0 was already adept at following user instructions, but GPT-4.1 is noticeably more precise. It was explicitly trained to follow instructions literally and exactly where appropriate. This means it’s less likely to deviate from formatting requirements, ordering of steps, or specific constraints given by the user. OpenAI reports a 10.5% absolute improvement on a benchmark measuring complex instruction following (Scale’s MultiChallenge) compared to GPT-4.0. In practical terms, GPT-4.1 reduces the need for users to perform prompt engineering or to repeatedly correct the AI’s output format. However, one side-effect is that GPT-4.1 can be more literal – it may stick exactly to what was asked, whereas GPT-4.0 might have taken a bit more creative liberty. OpenAI noted this literalness, saying GPT-4.1 “tended to be more ‘literal’ than GPT-4o” and sometimes requires more explicit prompts for creative tasks. Overall, steerability (the ease of getting the model to do what you intend) is improved in 4.1.

• Coding and Technical Skills: This is perhaps the most dramatic leap from 4.0 to 4.1. GPT-4.0 was considered very strong in coding tasks (it could write functioning code, debug, and explain algorithms well), but GPT-4.1 excels at coding to an even greater degree. On OpenAI’s SWE-Bench (a software engineering benchmark of coding challenges), GPT-4.0 solved about one-third of tasks, whereas GPT-4.1 solves over half. Specifically, GPT-4.1 achieved 54.6% on the human-validated SWE-Bench (versus ~33% for GPT-4.0). This outperforms even an intermediate GPT-4.5 Preview model, which scored around 38% on the same test. GPT-4.1’s coding improvements include writing cleaner code with far fewer unnecessary edits, adhering to provided function signatures or formats, and better multi-language support. OpenAI optimized it for “frontend coding, making fewer extraneous edits, following formats reliably, [and] consistent tool usage” in coding scenarios. This makes GPT-4.1 particularly powerful as a developer assistant – it can handle tasks like generating entire app components, performing code review, and even doing multi-step debugging with minimal user guidance.

GPT-4.1’s superiority in coding tasks is illustrated by OpenAI’s internal benchmark results (SWE-bench Verified). In this chart, higher bars indicate more tasks solved. GPT-4.1 (top bar, ~55% accuracy) dramatically outperforms the original GPT-4.0 (33%) on coding challenges, and even surpasses the interim GPT-4.5 preview model (38%). Smaller “OpenAI o-series” reasoning models and minis are shown for comparison. This leap in coding skill is one of the hallmark improvements of GPT-4.1.

• Long Context and “Memory”: GPT-4.1 introduced the ability to maintain and utilize an extremely large context. All three GPT-4.1 models can handle up to 1,047,576 tokens (≈1M) in the prompt. By comparison, GPT-4.0 maxed out at 32K tokens in special cases, and more commonly 8K. This means GPT-4.1 can be given entire books, massive legal contracts, or multiple research papers at once and can reason across them. Benchmarks created by OpenAI to test long-context understanding show GPT-4.1 setting new state-of-the-art results. For example, on a long video comprehension task (Video-MME with no subtitles), it scored 72% where GPT-4.0 scored ~65%. In practical use, GPT-4.1 is far better at “reading” lengthy inputs without losing track of details mentioned thousands of lines earlier. It is trained to focus on relevant parts of the input and ignore distractors even across very long text.

  This expansion of context also enhances what we might call the model’s working memory. In ChatGPT, GPT-4.0 sometimes struggled in very extended conversations or when a user pasted a large document, due to hitting context limits or forgetting earlier points. With GPT-4.1, such limits are effectively pushed much further out. Moreover, by mid-2025 OpenAI introduced a “Memory” feature in ChatGPT that allows the AI to remember information from your prior conversations (if you opt in) and use it to personalize responses. For instance, the model can recall your preferred writing style or that you mentioned specific needs in an earlier chat. While this is a ChatGPT feature (not purely model-driven), it complements GPT-4.1’s larger context window. The combination of long context and user memory means ChatGPT-4.1 feels more context-aware and can provide more relevant answers over long sessions.

• Tool Use and Integrations: Another major advance in this generation is how the model interacts with tools and external systems. GPT-4.0 was extended in mid-2023 with function calling capabilities and the ChatGPT Plugins ecosystem, allowing it to perform actions like web browsing or running code when explicitly invoked by the user. However, GPT-4.0 would not decide on its own to use a tool; users had to choose the “Browse” mode or ask the model to use the code interpreter, etc. By contrast, GPT-4.1 (and related new models like OpenAI’s o-series) are trained to use tools agentically – meaning the AI can determine for itself when to call an available tool to better answer the user. In April 2025, OpenAI introduced OpenAI o3 and o4-mini reasoning models in ChatGPT, which for the first time could autonomously leverage all of ChatGPT’s tools (web search, Python, file uploads, image generation, etc.) during a single conversation. This represents a step toward an AI “agent” that can chain reasoning with actions. GPT-4.1 itself was also “trained on more tool use” – the OpenAI Cookbook (developer guide) recommends developers use the API’s tools/function calling with GPT-4.1 because it’s better at using them properly. In essence, ChatGPT-4.1 is more adept at things like: searching the web when it lacks info, executing calculations in Python if asked a math heavy question, or producing an image if the user requests one – all with less hand-holding from the user. This dramatically improves its ability to handle complex, multi-step tasks (e.g. “Analyze this spreadsheet and then plot the data” would have GPT-4.1 run code behind the scenes). By mid-2025, these capabilities made ChatGPT feel closer to a general assistant that can combine tools + intelligence, whereas ChatGPT-4.0 was mostly just the intelligence unless manually extended.

• Performance and Efficiency: GPT-4.1 brings not only better raw capabilities but also optimizations in speed and cost. OpenAI reports that GPT-4.1 delivers “exceptional performance at a lower cost,” pushing forward performance at every point on the latency curve. The main GPT-4.1 model is roughly 26% cheaper to run than GPT-4.0 for the same work, thanks to training efficiencies and presumably architecture tweaks. In the API, the pricing was slashed – for example, GPT-4.1 usage costs about $2 per million input tokens (and $8 per million output tokens). By contrast, the original GPT-4 API was an order of magnitude more costly (around $0.03 per 1K tokens, i.e. ~$30 per million tokens) and had much lower limits on context. This cost reduction has big implications: developers and users can afford to use larger contexts and more queries with GPT-4.1. It also allowed OpenAI to remove or raise the message caps for Plus users. Initially, ChatGPT-4.0 was limited (e.g. 25 messages every 3 hours at launch) due to its computational expense; those restrictions were eased over time and by 2025 GPT-4.1’s efficiency made them unnecessary for most users.

  Additionally, the GPT-4.1 Mini and Nano variants are tailored for speed. GPT-4.1 Nano is described as “our fastest and cheapest model available,” ideal for quick autocomplete or classification tasks. It sacrifices some accuracy but still performed impressively on evaluation benchmarks (e.g. Nano scored 80% on MMLU, a knowledge test, beating GPT-4.0 Mini’s 77%). GPT-4.1 Mini nearly matches GPT-4.0’s performance while reducing latency by almost half and cost by 83%. For the end user, this means when speed is more important than absolute accuracy, these faster models make ChatGPT responses nearly instantaneous. In the ChatGPT interface, GPT-4.1 Mini is offered as a “fast” option and even used automatically as a fallback for free users who exhaust their limited GPT-4 usage quota. Overall, GPT-4.1 offers a spectrum of performance modes, from the full-power model to lightweight ones, whereas GPT-4.0 only had the single (slow) full model in ChatGPT.

Release Timeline and Official Updates

Understanding how these models came to be requires looking at the timeline of releases and updates:

• March 2023 – GPT-4.0 Launch: OpenAI announced GPT-4 in March 2023 with a technical report and initially deployed it in ChatGPT Plus. It was a major leap over the GPT-3.5 model (ChatGPT Free at the time). GPT-4 introduced features like image understanding and vastly improved exam and benchmark scores. At launch, GPT-4’s knowledge cutoff was around September 2021, similar to ChatGPT-3.5’s, which later caused some confusion until it was slightly updated. Over the rest of 2023, GPT-4 (ChatGPT-4.0) underwent minor tweaks – e.g. OpenAI rolled out a June 2023 update (gpt-4-0613) that enabled function calling (for plugins and API) and improved reliability. In September 2023, ChatGPT (Plus) introduced Vision (image inputs) and Voice features, leveraging GPT-4’s multimodal ability for image analysis and a new text-to-speech model for voice responses. Web browsing was also offered as a beta (the Browse with Bing mode) intermittently – it was enabled in summer 2023, then disabled due to issues, and re-enabled by fall 2023 with Bing’s support.

• May 2024 – GPT-4o Mini and GPT-4 “Turbo”: In mid-2024, OpenAI began hinting at improved GPT-4 variants. On May 16, 2024 they introduced GPT-4o Mini, calling it “the most capable and cost-efficient small model” surpassing GPT-3.5 Turbo. Around this time, an improved version of GPT-4 (sometimes informally called GPT-4 Turbo) was also developed, likely with an updated knowledge base into 2023. These served as precursors to GPT-4.1: essentially iterative upgrades to keep ChatGPT’s performance growing. By late 2024, users observed GPT-4’s answers had become more up-to-date (knowledge cutoff extended into late 2023) and certain tasks were handled better, indicating continual training updates behind the scenes.

• Late 2024 to Early 2025 – GPT-4.5 Preview: OpenAI worked on a model referred to as GPT-4.5 (Preview), which was a provisional step between GPT-4 and a hypothetical GPT-5. GPT-4.5 Preview became available via API (and Azure OpenAI) around February 2025. It was a general-purpose model with some improvements in reasoning and the ability to handle images. However, GPT-4.5 did not outperform GPT-4.0 on every front; for example, it had moderate coding abilities (as noted, ~38% on a coding benchmark vs 33% for GPT-4.0). OpenAI used the “preview” period to get feedback and fine-tune alignment. Ultimately, with the advent of GPT-4.1 in April, OpenAI decided to deprecate GPT-4.5 Preview – announcing it would be turned off by July 14, 2025 in favor of GPT-4.1. The reasoning given was that GPT-4.1 offered equal or better capabilities at much lower cost and latency.

• April 2025 – GPT-4.1 Launch: On April 14, 2025, OpenAI officially launched GPT-4.1 along with the Mini and Nano variants. The launch was covered in detail by tech outlets. For example, The Verge highlighted that GPT-4.1 has a “larger context window and is better than GPT-4o in just about every dimension”. OpenAI’s own blog post and livestream demonstrated its coding prowess and long-context comprehension. It was made immediately available via the API/Playground for developers. Notably, OpenAI stated in the announcement that GPT-4.1 would not immediately replace GPT-4 in ChatGPT – instead, ChatGPT’s GPT-4 (GPT-4o) would gradually absorb improvements from 4.1 over time. This approach likely aimed to ensure stability for ChatGPT users.

• April 2025 (continued) – O-Series Reasoning Models: Just days after GPT-4.1’s debut, OpenAI also rolled out new “OpenAI O3” and “O4-mini” models in ChatGPT (April 16, 2025). These were described as the “smartest models... to date” for reasoning, trained to deeply reason and use tools agentically. While not branded as “GPT-4.1”, they are related advancements in the model lineup. O3 (presumably a version of GPT-4 with extended reasoning optimization) and O4-mini were given to all users (including free) to upgrade the baseline ChatGPT intelligence. This was an important shift: for the first time, even free users’ default model gained significant reasoning/tool-using abilities, narrowing the gap with Plus.

• May 2025 – ChatGPT Integration of GPT-4.1: By mid-May 2025, due to popular demand, OpenAI made the full GPT-4.1 model available in ChatGPT for Plus/Pro subscribers. Starting May 14, Plus users could open the model picker and select GPT-4.1 for their chats. This gave users direct access to the coding-optimized version, which many developers prefer for its stricter adherence and up-to-date knowledge. At the same time, GPT-4.1 Mini replaced GPT-4o Mini across ChatGPT for all users. In practice, this meant the “Fast” mode or default fall-back model in ChatGPT became GPT-4.1 Mini, which is more capable than the previous default (and better than GPT-3.5 Turbo). Free users who had limited access to GPT-4 capabilities could now indirectly benefit from GPT-4.1 Mini once they hit certain usage limits of the main model. OpenAI kept GPT-4o as the “default” GPT-4 model in ChatGPT (with updates), but users could explicitly choose GPT-4.1 if desired. Over the next months, we can expect GPT-4.1’s improvements to fully merge into the default model and for GPT-4.0 to be phased out (OpenAI indicated GPT-4 would be retired from ChatGPT by end of April 2025).

In summary, the timeline shows GPT-4.0 evolving gradually through 2024, and GPT-4.1 arriving in 2025 as a major upgrade. OpenAI’s strategy was to incrementally improve the GPT-4 lineage (hence versions 4.0, 4.0 mini, 4.5 preview, 4.1, etc.) rather than rushing out GPT-5. In fact, Sam Altman announced that GPT-5 was delayed beyond the originally expected timeline, indicating OpenAI put focus on refining GPT-4-based models like 4.1 before the next paradigm leap. By mid-2025, ChatGPT’s “GPT-4” offering is substantially more powerful and feature-rich than the original GPT-4.0 at launch, thanks to these updates.

ChatGPT Implementation (Free vs Pro) and API Availability

Another way to compare ChatGPT-4.0 and 4.1 is how they are deployed and who can access them. The improvements in GPT-4.1 coincided with changes in ChatGPT’s service tiers and API:

• ChatGPT Free Tier: Originally, free users only had access to the GPT-3.5 model (Turbo). GPT-4 (4.0) was exclusive to paid subscribers. This remained mostly true through 2023–2024. By 2025, OpenAI started bridging the gap slightly – for example, introducing GPT-4o Mini as an upgraded default model for everyone in April 2025. This gave free users a taste of GPT-4-level reasoning, as the o4-mini model could use tools and had improved intelligence. With GPT-4.1’s advent, OpenAI has a concept of free GPT-4 usage limits: free users might be allowed a small number of GPT-4 powered messages (to entice upgrades), after which ChatGPT falls back to a smaller model. GPT-4.1 Mini now serves as that fallback for free users. In short, free users benefit indirectly from GPT-4.1’s efficiency – the baseline model they interact with is more capable than the old GPT-3.5, though they still don’t have unlimited access to the full GPT-4.

• ChatGPT Plus ($20/mo): Plus users since March 2023 have had access to GPT-4 (original). For most of 2023–24, Plus meant you could choose GPT-4 (and use new beta features like browsing or code interpreter) while free was limited to GPT-3.5. After GPT-4.1’s release, Plus (and the new Pro tier, see below) users can choose between multiple GPT-4 based models: the default GPT-4 (which OpenAI updates periodically, known as GPT-4o latest) or the new GPT-4.1 model via the “More models” menu. Using GPT-4.1 on Plus has the same rate limits as GPT-4.0 did (e.g. number of messages per minute), so OpenAI did not impose extra restrictions. Essentially, ChatGPT Plus users as of mid-2025 get both versions of GPT-4: the general-purpose one and the coding-optimized one, alongside GPT-3.5 Turbo and other tools. This is a direct implementation difference: ChatGPT-4.0 (original) was the single option before, whereas now ChatGPT-4.1 is an additional option for subscribers.

• ChatGPT Pro / Team: OpenAI introduced higher tiers like Pro (for individual power users) and Team (for organizations) in late 2024/early 2025. These plans offer higher rate limits, priority access and sometimes early features. Both Pro and Team users have the same model options (GPT-4.0, GPT-4.1, etc.), just with more usage capacity. For instance, on launch, GPT-4.1 was immediately enabled for Plus, Pro, and Team users, with Enterprise and EDU customers to follow shortly. The distinction is mostly in usage volume rather than model difference. (Pro users might be able to send more messages per minute or use the 32K context if available, etc.) The key point is that GPT-4.1 remains a premium feature – accessible to paying users (Plus/Pro/Enterprise), not to regular free accounts directly.

• API Access: GPT-4.0 was made available via the OpenAI API on a limited basis starting in 2023 (initially waitlisted, then gradually open to all API developers with a usage quota). Developers could call "gpt-4" or "gpt-4-32k" models to get GPT-4’s capabilities in their own apps. GPT-4.1, upon launch, is available via API immediately to all API users (no waitlist mentioned). The API has endpoints for gpt-4.1, gpt-4.1-mini, and gpt-4.1-nano. Notably, OpenAI decided that GPT-4.1 full model will only be via API (for now) and not directly replace ChatGPT’s default model. Instead, ChatGPT’s default GPT-4o model gets better over time. This means if a user specifically wants to leverage all of GPT-4.1’s power (especially the 1M token context), using the API is necessary, since the ChatGPT UI might impose its own limits.

  The API pricing for GPT-4.1 is dramatically lower than GPT-4.0’s was, making it attractive for developers. As mentioned, GPT-4.1 costs $2 per 1M input tokens and $8 per 1M output tokens (so roughly $0.002 per 1K input tokens). GPT-4.0’s pricing was around $0.03 per 1K tokens input and $0.06 per 1K output, so GPT-4.1 is about 10× cheaper for inputs and ~8× cheaper for outputs – a huge reduction. This will likely accelerate adoption of GPT-4.1 via API for applications requiring large contexts (like feeding entire books or code repositories into the model, which would have been prohibitively expensive with GPT-4.0).

• Enterprise and Domain-Specific: ChatGPT Enterprise (launched August 2023) gave enterprises unlimited GPT-4 access at a higher price. By 2025, Enterprise customers likely have access to the improved GPT-4 (and possibly custom model options). OpenAI has also hinted at fine-tunable models coming (GPT-4 Turbo with fine-tuning, etc.). While not exactly “ChatGPT-4.1 vs 4.0,” it’s worth noting that the product integration of these models has expanded. For example, in 2025 OpenAI introduced Connectors and Deep Research modes in ChatGPT for business users. These allow ChatGPT to connect to internal company data and use GPT-4 models to generate reports with citations. Such features rely on the advanced reasoning of GPT-4. With GPT-4.1’s improvements (especially tool use and long context), these business features have become more powerful (e.g. analyzing thousands of documents from SharePoint or Dropbox using the model’s 1M token window).

In summary, GPT-4.0 was a Plus-only model in ChatGPT and a premium API offering; GPT-4.1 remains behind the paywall as well, but gives subscribers more choice and gives developers a far more scalable model via API. Free users benefit indirectly through improved default models (GPT-4.1 Mini) but don’t have full access to GPT-4.1’s capabilities without upgrading.

User-Facing Features and Integrations

From a user’s perspective, the evolution from ChatGPT-4.0 to 4.1 also comes with changes in features and how one interacts with the AI. Here are some user-facing aspects to compare:

• Memory and Personalization: ChatGPT-4.0 sessions were stateless beyond the chat history in the current conversation – the model couldn’t recall what you talked about last week in a different thread. To address this, OpenAI introduced Custom Instructions in mid-2023 (letting users set preferences that GPT-4 would always see at the start of conversations) and later an expanded Memory feature in 2024–2025. By ChatGPT-4.1’s time, the Memory feature could “reference your recent conversations to deliver more relevant responses” (for those who opt in). This means ChatGPT-4.1 feels more personalized; for example, if you told it your occupation and goals in a prior session, it can incorporate that context in future answers. GPT-4.0 did not have this capability in early 2023. Thus, ChatGPT-4.1 provides a more continuous user experience, where the AI “remembers” context across sessions (while still respecting privacy settings).

• Browsing and Current Information: GPT-4.0 had a fixed knowledge cutoff and relied on the Browsing tool to fetch recent information. Initially, browsing was a bit clunky and was disabled for a period. By late 2023, ChatGPT’s Browse with Bing allowed GPT-4 to search the web when asked, but it was an extra mode the user had to turn on. With GPT-4.1 and the new reasoning models, browsing is more seamlessly integrated. The model (especially the o-series) can decide to search when it encounters a question about recent news or a web link. From a user standpoint, ChatGPT-4.1 is much better at handling questions like “What happened in the tech world yesterday?” – it can actually look up the answer if allowed, whereas ChatGPT-4.0 would previously apologize that it cannot browse (if the mode wasn’t enabled). The free-form integration of browsing means users no longer have to explicitly toggle modes as often; the AI will use tools like search or calculators as needed. This makes interactions more natural and powerful in ChatGPT-4.1.

• Plug-ins and Tools: In May 2023, OpenAI introduced ChatGPT Plugins (such as Expedia for travel, Wolfram for math, etc.) for Plus users. GPT-4.0 could use these plugins, but again only when the user specifically activated them and within separate plugin mode conversations. With GPT-4.1, thanks to function calling improvements, the ecosystem of Connectors/Plugins is more unified. OpenAI in 2025 launched Connectors in “deep research” mode which allow ChatGPT to tap into services like Google Drive, Outlook, or internal APIs to gather information. GPT-4.1’s ability to juggle multiple tools in one conversation (search, then use a file from Drive, then maybe call a calculator) is a new convenience. This means a user can issue a complex request (e.g. “Analyze my last 100 emails for action items”) and ChatGPT with GPT-4.1 can combine tools to accomplish it, whereas GPT-4.0 would have needed the user to manually use one plugin at a time. Essentially, ChatGPT-4.1 turns the tool plugins into a toolkit it can manage itself.

• Vision (Image Input/Output): GPT-4.0’s multimodal capability was famously demonstrated with image inputs (e.g. describing images or interpreting memes). This Vision feature rolled out to Plus users around October 2023. GPT-4.1 retains full multimodal abilities and was additionally tested on vision benchmarks that involve not just static images but also understanding visual data in a logical context (like charts or video frames). For users, ChatGPT-4.1 can analyze more complex visual prompts and possibly more types of media. On the output side, ChatGPT with GPT-4.0 gained image generation capability in late 2023 by integrating DALL·E 3 (users could ask ChatGPT to create images). The Verge noted that in March 2025 GPT-4o was updated to include image generation in ChatGPT. This was extremely popular – to the point OpenAI had to temporarily limit usage due to GPU load. With GPT-4.1’s release, image creation remains available, and the improved models can even better follow image-generation instructions. The only caveat: certain new models (like the specialized o3-pro) did not support image output initially, but users could fall back to GPT-4 or o4-mini for that. In any case, from a feature set perspective, ChatGPT-4.1 offers the same or expanded Vision features as 4.0, allowing both interpreting images you send and generating new images on request.

• Voice and Multimodal Output: ChatGPT introduced voice conversation (text-to-speech for answers, and voice input from user on mobile) in late 2023 for Plus. This works across models, including GPT-4. GPT-4.1 doesn’t directly change voice, but the overall conversational experience in voice can be improved by its better instruction-following (leading to more concise answers when appropriate, for instance). In June 2025, OpenAI upgraded the Advanced Voice to be more natural and emotive. This upgrade is model-agnostic but complements the improved empathy and nuance that GPT-4.1 can exhibit thanks to training on following tone hints. So, using ChatGPT-4.1 via voice feels even more lifelike than GPT-4.0 did.

• Output Style and Alignment: Users may notice subtle differences in how GPT-4.0 vs GPT-4.1 respond. GPT-4.0 sometimes gave very lengthy answers or hedged with cautious language due to alignment rules. GPT-4.1’s updates aimed to make it “more proactive” and “better at guiding conversations toward productive outcomes”. This means ChatGPT-4.1 might ask clarifying questions more often, or suggest next steps to the user instead of waiting. It also has improved refusal behavior tuning – e.g. after the April 2025 sycophancy fix, it became less likely to agree to a user’s misleading premise and more likely to correct them or politely push back. From the user perspective, GPT-4.1 can feel more assertive and helpful, whereas GPT-4.0 might have been extremely polite to a fault. Safety-wise, both models have guardrails, but researchers found GPT-4.1 may take more risks in generating disallowed content if not properly fine-tuned. This is an area OpenAI is continuously working on – users might not directly see it, but behind-the-scenes policy and prompt updates are being applied to keep GPT-4.1’s outputs safe and on track.

In essence, the ChatGPT interface and experience evolved along with the model. ChatGPT-4.1 provides a more integrated AI assistant: it remembers context better, can browse and use tools on its own, handles images and voice smoothly, and follows user preferences more closely. ChatGPT-4.0 was a powerful model, but the user often had to manage its limitations (short memory, needing to toggle modes, etc.). With 4.1, a lot of that friction is reduced, making the interaction more seamless and powerful for the end-user.

Performance Benchmarks and Evaluation

To quantify the differences between GPT-4.0 and GPT-4.1, we can look at various benchmark tests and performance metrics reported by OpenAI and third parties:

• Coding Benchmarks: We’ve noted the SWE-Bench Verified result (≈33% vs 55% for GPT-4.0 vs GPT-4.1) which demonstrates a huge improvement in coding reliability. GPT-4.1 was explicitly optimized for coding tasks and it shows. Another coding evaluation, Aider’s polyglot diff benchmark, measured how well the model handles code differences across languages – GPT-4.1 scored ~52.9%, indicating strong ability to apply changes in multiple programming languages. Moreover, GPT-4.1 reduces erroneous code modifications (only 2% extraneous changes vs 9% for GPT-4.0). This means when it’s asked to fix or refactor code, it’s much more precise. TechCrunch reported that despite these gains, top competitor models still scored slightly higher on some coding tasks (e.g. Google’s Gemini 2.5 Pro with 63.8%), but GPT-4.1 narrowed the gap significantly while being cheaper.

• Knowledge and Academic Benchmarks: Both GPT-4.0 and 4.1 are tested on tasks like MMLU (Massive Multitask Language Understanding, covering academic exams). GPT-4.0’s original score on MMLU was around 86.4% (as per the GPT-4 technical report). GPT-4.1 pushed this further – one table indicates GPT-4.1 scored 90.2% on MMLU, a solid improvement, whereas GPT-4.1 Mini scored 87.5% (comparable to GPT-4.0). These are state-of-the-art level results, reflecting that GPT-4.1 retains general knowledge and reasoning improvements, not just coding. On specialized evaluation like AIME 2024 (an AI medicine exam) and GPQA (a question-answering test), GPT-4.1 also outperformed GPT-4.0. For instance, GPT-4.1 improved by ~10% absolute on an instruction-following benchmark and set a new high score on a long-context video understanding task. In general, any standard benchmark (math, logic, science questions, etc.) that GPT-4.0 did well on, GPT-4.1 tends to do as well or better. The only area where GPT-4.1 might appear weaker is if the test favored more creative or lenient answers – GPT-4.1’s literalness might score lower in some evaluations that reward “human-like” casual responses, but this is subtle.

• Long Context Performance: OpenAI created internal benchmarks for the new 1M token context ability, such as multi-round coreference tests (finding references deep in a synthetic conversation) and Graphwalks (having the model simulate a graph traversal over a huge context). GPT-4.1 performed extremely well on these, whereas GPT-4.0 obviously could not even attempt them beyond 32K tokens. Interestingly, OpenAI did note that performance degrades as context approaches the extreme length – e.g. on a test called OpenAI-MRCR, GPT-4.1’s accuracy dropped from ~84% at 8K context to ~50% at 1M context. This indicates that while the model can handle long input, it may not maintain top precision when absolutely flooded with information. It’s a known limitation: even humans would struggle with millions of words at once. Techniques to mitigate this (like retrieval or summarization strategies) may be needed, but the important part is GPT-4.1 at least offers the capability to attempt such tasks, whereas GPT-4.0 could not.

• Multimodal & Vision: On image-based benchmarks like MMMU (answering questions about images) and MathVista (solving math problems with visual components), GPT-4.1 was evaluated and showed improvements over GPT-4.0. For example, GPT-4.1 outperformed GPT-4.0 on interpreting charts (CharXiv benchmark) and on complex visual math problems. This suggests the vision component of GPT-4.1 was fine-tuned to be more accurate. Both models can describe images well, but GPT-4.1 is a bit better at extracting specific details or combining visual info with text context (likely due to better long-context handling as well).

• Tool-use Evaluation: One indirect way to evaluate the models is how well they perform when they have tools. OpenAI likely tested GPT-4.1’s success rate in invoking the correct function API calls when needed. The Wikipedia entry notes that the OpenAI cookbook recommends using the tools API with GPT-4.1 because it was “trained to exclusively use the tools field” properly. This means the model will follow the protocol (e.g. outputting a JSON for function calls) more reliably than GPT-4.0 did, which sometimes needed a bit of coaxing. In user terms, GPT-4.0 might have occasionally given a direct answer instead of calling a tool, whereas GPT-4.1 is more likely to cooperate with the intended tool usage. That improves the performance of agent-like tasks (the AI completing a job by using external functions correctly). Early anecdotal reports from developers and users generally confirm that GPT-4.1 is less likely to “hallucinate” a tool that doesn’t exist and more likely to use ones that do, making it easier to build applications on top of it.

• Benchmark Limitations: It’s worth mentioning that benchmarks don’t capture everything. For instance, alignment and safety evaluations are also critical. OpenAI runs internal red-teaming and behavioral tests. GPT-4.0 was considered a big step up in alignment from GPT-3.5 (refusing to produce harmful content more reliably). GPT-4.1 underwent safety evals too, but external researchers like Owain Evans and the team at SplxAI found evidence that GPT-4.1 could be more misaligned in certain ways than GPT-4.0. They didn’t specify in the snippet, but this could mean GPT-4.1 might more readily produce risky outputs if cleverly prompted, perhaps due to its increased knowledge and tool use capability. OpenAI is likely addressing these issues with frequent model updates (for example, the April 29, 2025 update rolling back a problematic change that made GPT-4o too gullible). From a performance perspective, accuracy and safety must be balanced. GPT-4.1 pushes accuracy and capability boundaries, but ensuring it remains as safe as (or safer than) GPT-4.0 is an ongoing effort. For most benign queries, users will just notice it’s smarter and more up-to-date; for adversarial prompts, OpenAI’s filters and policies will kick in similarly to before, possibly with extra rules learned from new data.

• Speed and User Perception: Not formally a benchmark, but in everyday use, speed is a performance metric that users care about. As discussed, GPT-4.0 was relatively slow – taking several seconds (or tens of seconds for long answers) to respond. GPT-4.1’s improved efficiency means responses come quicker. Many Plus users reported that GPT-4.1 (or the new default GPT-4 after updates) feels snappier and more responsive, especially for short queries. The Mini model in ChatGPT is extremely fast, often responding nearly as quickly as the older GPT-3.5 Turbo did, but with better quality. This increase in speed greatly improves the user experience when interacting or iterating on a task.

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So... ChatGPT-4.1 marks a significant upgrade over the original ChatGPT-4.0 across virtually all dimensions. It builds on the foundation of GPT-4’s advanced reasoning and language abilities while addressing its main pain points – limited context, slower speed, and areas of weaker performance like specific coding tasks. With a 1,000,000-token context window, updated knowledge base (2024), and enhanced tool-using capabilities, GPT-4.1 is a more powerful and versatile AI assistant. Users benefit from more accurate and relevant answers, whether for writing code, analyzing large documents, or getting up-to-date information with sources.

From a deployment standpoint, GPT-4.1’s introduction also reflects OpenAI’s strategy of iterative improvement. Rather than a brand-new “GPT-5” in 2024, we saw gradual enhancements (GPT-4 Turbo, 4o Mini, 4.5 Preview) culminating in the refined GPT-4.1 by 2025. This allowed OpenAI to integrate new features (like tool use, multimodal inputs, long memory) in a controlled way. By mid-2025, ChatGPT Plus users have an AI that is noticeably more capable than what launched in early 2023: it can write complex code with fewer errors, handle entire research projects worth of data, and even autonomously decide when to browse or calculate to give you a better answer.

That said, GPT-4.1 is not without challenges. Its literalness means users must be clear in what they ask, and the sheer scale of its context window raises expectations (and costs) for certain tasks. Safety and alignment remain ongoing concerns as models get more powerful. OpenAI has shown awareness of these, rolling back changes when things go awry (e.g. the “overly agreeable” behavior fix) and planning additional improvements. We can anticipate further updates (GPT-4.2 or GPT-5 in the future) that will continue this trajectory – improving reasoning, introducing long-term memory, or integrating new modalities – all while trying to keep the AI safe and reliable.

In summary, ChatGPT-4.1 vs 4.0 can be seen as evolution vs revolution: GPT-4.0 was revolutionary at its debut, and GPT-4.1 evolves those capabilities to be sharper, more efficient, and more user-friendly. For professionals and developers, GPT-4.1 is a welcome upgrade especially in specialized domains like programming. For everyday users, many improvements (like faster responses and better context handling) are seamlessly behind the scenes, making interactions with ChatGPT more productive. As of mid-2025, ChatGPT with GPT-4.1 represents one of the most advanced conversational AI systems available, bridging the gap between human-like understanding and practical tool-assisted problem solving.

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