All ChatGPT models available today: features, differences, and how to choose the right one (July 2025 update)

What families of models can you choose from on ChatGPT today

The offering of ChatGPT models in 2025 is far more complex than in previous years, marking a race increasingly aimed at optimizing power, speed, costs, and response specialization. If until recently the distinction was only between “latest model” and “legacy model,” today the choice moves between models designed for speed, others focused on reasoning depth, versions created for multimodality, and hybrid solutions. Each model family reflects precise use needs: from unlimited free conversation to advanced business prototyping, from professional coding to image analysis or real-time voice data. This range of options marks a turning point for both private users and those developing services on the OpenAI platform, who can now fine-tune their experience for specific objectives, calibrating costs and performance as never before.

GPT-4o: the versatile model focusing on voice, images, and human-level speed

GPT-4o, where the “o” stands for “omni,” is today the standard ChatGPT model for both free and Plus subscribers. This version, launched in spring 2024, stands out as natively multimodal: not just text, but also images, audio, and, in limited rollout, the ability to process short video. The most impressive aspect remains its rapidity in audio response, with times comparable to a human conversation. Qualitatively, GPT-4o delivers results at the GPT-4 Turbo level in English and even better in less common languages, consolidating its international leadership. Today all users start from GPT-4o; when the message limit is reached on the free plan, the system now falls back to GPT-4.1 mini, not GPT-3.5, keeping costs low while ensuring universal access. On the API side, GPT-4o has halved costs compared to its predecessor, allowing businesses to scale multimodal solutions sustainably.

GPT-4o employs an advanced architectural structure enabling native integration of multimodal input without needing separate modules for images or audio, with an average latency in voice responses of about 320 ms. It can process text inputs up to 128k tokens and handles multiple languages with greater accuracy than previous versions. On benchmarks like MMLU it achieved scores equal to or higher than GPT-4 Turbo, demonstrating versatility even in complex tasks. The rollout of video features and advanced APIs is ongoing, with progressive expansion of voice features for free users as well, always within server load limits.

GPT-4.5: the search for creativity and knowledge depth (phasing out)

For several months, GPT-4.5 represented OpenAI’s latest experiment in unsupervised scalability, trained on even larger datasets with less human correction. The model was designed for idea generation, creative writing, and hallucination reduction more than step-by-step reasoning. However, OpenAI has already announced the official deactivation of GPT-4.5 preview from July 14, 2025, both in the API and ChatGPT Pro, in order to focus resources on newer models like GPT-4o and GPT-4.1.

Technically, GPT-4.5 was characterized by deeper training on data updated post-2023 and broader encyclopedic coverage, with advanced generalization capacity. In benchmarks like TriviaQA and BigBench it outperformed GPT-4o on general knowledge and creative questions, but the context limitations (128k tokens) and lack of Voice Mode and Python tools had already reduced its broad adoption. The scheduled retirement of GPT-4.5 marks a streamlining of the range, in favor of more high-performance and multimodal architectures.

o3 and o3-pro: the new generation for advanced reasoning, with o3pro now also available to Pro users

The o3 and o3-pro models are at the heart of OpenAI’s new strategy for advanced reasoning. These models excel in solving complex problems, code writing, scientific analysis, and image understanding. O3 reduces critical errors by 20% compared to the previous generation (o1) and demonstrates notable ability to autonomously decide when to consult the web, execute Python code, or generate images. O3-pro, initially reserved for Enterprise and Anchr, since June 2025 is also accessible to ChatGPT Pro subscribers, extending availability to advanced non-enterprise users. O3-pro delivers even deeper and more accurate answers on high-difficulty questions, even though it takes more time to produce output, making it ideal for edge cases or advanced technical queries. This family is the preferred choice for those seeking not just a good conversation, but true specialist assistance on complex topics.

The o3 architecture leverages new-generation chain-of-thought reasoning models, able to auto-select additional tools such as browsing, Python runtime, and DALL-E image generation without explicit user input. In math and logic benchmarks (GSM8K, MATH, HumanEval) it consistently outperforms predecessors, with a critical error rate below 5%. O3-pro, now also available to Pro, further increases response depth and accuracy but with higher latency; the share of “incomplete” answers drops to an all-time low, making the model ideal for decision processes and automation in structured, mission-critical workflows.

o4-mini and o4-mini-high: speed and efficiency for high-volume chats

The o4-mini series was created to offer the best intelligence possible in a “small size.” These models are surprisingly fast, low-cost, and capable of handling complex reasoning compared to other models of the same size, as confirmed by the latest AIME 2025 benchmarks. On ChatGPT, you can choose between the standard variant and the high one: the latter favors longer chains of reasoning at the cost of slightly higher response times. O4-mini is the best choice for those who need to handle many chats at once, for business use or customer care, and still want smart, reasoned answers without paying for top-tier models. The balance between price, latency, and quality is its real strength.

The o4-mini and o4-mini-high variants are optimized for minimal latency, with average response times under 150 ms and a context window up to 64k tokens. In the AIME 2025 rankings, the model outperformed competitors of similar size both on reasoning tasks and applied problem-solving tests. O4-mini-high implements a longer and more detailed reasoning chain, sacrificing speed slightly but improving the logical quality of responses—ideal in workflows where depth is needed but rapid answers and low costs are still a priority.

GPT-4.1 and GPT-4.1 mini: ultra-long context and reliable code

GPT-4.1 is the natural evolution of the GPT-4 family, with a particular focus on coding, rapid analysis, and management of extended contexts. It can handle up to one million tokens per input (API only in the full version), while the mini variant is now present on ChatGPT both as a selectable model and as fallback for the free plan. Its performance on technical benchmarks, such as SWE-bench Verified, place it at the top of its category, with the ability to follow complex instructions better than any previous model. This solution is designed for those who want the best in coding and data management, with maximum operational efficiency and greater speed than top models.

Technically, GPT-4.1 has been trained on expanded datasets with advanced programming patterns, software use cases, and technical documentation, supporting input up to 1 million tokens per API session. Output quality in code diffs has been improved with the addition of automatic validation sequences, while the instruction-following rate exceeds GPT-4o by more than 10% in MultiChallenge tests. The mini model offers half the latency of standard versions and allows even more efficient management of intensive sessions on large data volumes and requests.

GPT-3.5: the silent engine of low-cost APIs (still available via API only)

Although it no longer appears as fallback on the free plan, GPT-3.5 remains the backbone of OpenAI’s API offering. Today it is no longer automatically used by ChatGPT Free (the system now falls back to GPT-4.1 mini), but it is still widely used for prototypes, extremely high-volume services, and all those applications where speed and minimum cost are more important than reasoning depth. Its presence is guaranteed at least until the second half of July 2025 on both OpenAI and cloud providers such as Azure.

GPT-3.5 is optimized for minimum server resource consumption, with API costs among the lowest on the market (less than $0.001 per thousand tokens). The maximum context window handled via API is 16k tokens, and the instruction-tuned (0914) version remains active and updated on major cloud platforms at least until July 16, 2025. Response speed remains competitive, while the hallucination rate and reasoning capability are lower than newer versions, but still adequate for prototyping, testing, or massive standard information requests.

The future of names and availability: what will happen to current models and what will the next model be called

In recent months, the debate around model names and their future has become central for those following the evolution of ChatGPT and OpenAI. According to the latest official statements, GPT-4.5 will be discontinued from July 14, 2025; as for GPT-3.5, there is no definitive retirement date, but support is confirmed at least until the end of July, with probable extension on the API and cloud platforms side. There are no immediate changes planned to the nomenclature of other models until the arrival of the next generation.

For the next major model, OpenAI has publicly mentioned “GPT-5,” but it is still under discussion whether to maintain this numbering or introduce a new acronym, partly due to the convergence between GPT and the “O” series models. The launch is expected “in summer 2025,” but without a precise date, and the transition will happen without interruption of existing services: a phase of coexistence between legacy and new models is expected, with automatic fallback and progressive updates. Current roadmaps confirm that any deprecation will be announced in advance and that the platform will continue to offer backward compatibility and stability, including for clients who need continuity for business workflows.

When will available models change: current roadmap and certainties

OpenAI has confirmed that none of the most widely used models (GPT-4o, o3, o4-mini, GPT-4.1) will be removed before the end of 2025, with the sole exception of GPT-4.5 preview, whose discontinuation is already official. The fallback system for free users is now stably on GPT-4.1 mini. Any future changes, including the debut of the new “GPT-5” acronym or a possible naming change, will be announced well in advance and accompanied by transition periods to avoid any service interruptions.

OpenAI aims to unify the platform by reducing the importance of individual model names, pushing toward increasingly multimodal and agentic models where the system itself will select the best combination for the required task, while still leaving manual selection available for advanced users. All updates regarding roadmap, deprecation timelines, and introduction of new names will be published in official notes, so companies and developers can confidently plan the continuity of their ChatGPT-based applications.

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