ChatGPT vs Claude for PDF Reading: Complete Feature-by-Feature Comparison
- Graziano Stefanelli
- 5 days ago
- 7 min read
ChatGPT and Claude are two of the most advanced AI models for reading and analyzing PDF documents.
Both can extract, summarize, and interact with content inside files uploaded by the user. Yet, they differ significantly in how they handle images, scanned pages, large documents, and multi-step workflows.
Here we break down their capabilities side by side, covering upload methods, parsing logic, visual support, navigation tools, and more.
1. PDF Upload and Input Methods
ChatGPT
Files are uploaded directly in the web or mobile chat interface using the paperclip icon. This feature is available to users on Plus and Enterprise plans. The maximum file size allowed is 512 MB, with a processing cap of 2 million tokens per file. On GPT-4o, users can upload up to 80 files every 3 hours. Free-tier users are limited to 3 files per day, and each conversation allows a maximum of 20 uploaded files. Embedded images in PDFs are discarded unless the user is on an Enterprise plan with “Visual Retrieval” enabled.
Claude
PDFs can be uploaded via drag-and-drop in the chat or through the Claude API using a file URL, base64 content, or file ID. In the chat interface, the maximum file size is 30 MB; the API allows up to 32 MB. For visual analysis, the document must not exceed 100 pages. Files beyond this length are processed as text-only. Users can attach up to 20 files per chat, with additional uploads possible when using Claude’s knowledge base, as long as the total content fits within the context window.
Platform | Upload interface | Max file size | Visual page limit | Files per chat / window |
ChatGPT | Web & mobile (paperclip) | 512 MB | Not page-based (token-limited) | 80 files / 3 h (GPT-4o); 3 / day (free); 20 per conversation |
Claude | Chat; API (URL, base64, file_id) | 30 MB (chat) / 32 MB (API) | 100 pages | 20 files per chat |
2. PDF Parsing and Content Recognition
ChatGPT
Extracts text accurately from digital-text PDFs and respects basic document structure such as headings and paragraphs. Scanned pages and photographs inside PDFs are ignored unless a prior OCR step adds a text layer; the built-in vision mode focuses on describing visible images rather than converting them to selectable text. Complex tables and multi-column layouts are flattened into plain text, which can reduce positional accuracy for numbers and labels. Best suited for clean, text-centric documents under the 2-million-token processing cap.
Claude
Runs a single-pass pipeline that combines OCR, layout analysis, and vision. Scanned or image-only pages are converted into machine-readable text on upload, so users can query them immediately. The model recognises tables, charts, and figures, returns them in conversational form, and—on request—packages key fields as structured JSON for downstream use. Vision handling is available for PDFs up to 100 pages; longer files are parsed as text only. Performance holds up on skewed scans and multi-column spreads, making Claude the stronger choice for mixed-format or image-heavy documents.
Feature | ChatGPT | Claude |
Text extraction (embedded) | ✓ | ✓ |
OCR for scanned pages | External tool required | Built-in |
Visual element analysis | Descriptive only | Full analysis |
Structured data output | Basic | Advanced (JSON) |
Complex table handling | Moderate | Robust |
Page limit for vision | Not applicable | 100 pages |
3. Interaction and Usability
ChatGPT
Once a PDF is uploaded, it appears as an attachment within the chat. There is no split-screen viewer; all interaction takes place through chat-based commands and questions. Users can ask about the content, search for specific terms, request summaries, or extract sections by page or keyword.
The conversation naturally maintains context, so users can follow up or refine questions without repeating themselves. Prompt suggestions often appear for actions like search or extract, streamlining the process for routine queries.
For ongoing work, files and related chats can be organized in a workspace, making it easy to revisit documents and continue previous threads without re-uploading. In advanced modes, detailed citations or sources may be included with responses.
Claude
After upload, PDFs display as thumbnail previews and can be opened in a split-screen mode with the document on one side and the chat on the other. Users can click on citations or references within responses to highlight and navigate to the exact page in the document.
Claude automatically includes page numbers in citations and enables direct navigation by clicking them. Users can ask for specific visual elements, like zooming in on a chart or image, and the chat interface responds with contextual previews or snapshots.
Multiple PDFs can be managed within a single chat session or in a knowledge base, supporting cross-document questions and comparisons. All interactions retain context, allowing for in-depth, multi-step exploration of even complex or lengthy documents.
Feature | ChatGPT | Claude |
In-chat Q&A | Context-aware follow-ups | Context-aware follow-ups |
Document preview | Attachment icon | Split viewer with thumbnails |
Navigation to specific pages | Manual (by prompt) | Clickable, automatic highlights |
Search and extract commands | Prompt suggestions | Built-in, via chat or clicks |
Multi-document support | Workspace/projects | Multi-file chat, knowledge base |
Visual interaction | Limited to text or citations | Native zoom and snapshots |
Citations/page numbers | Advanced mode, optional | Default, always included |
4. Search and Navigation Features
ChatGPT offers both keyword search and semantic retrieval within uploaded PDFs. Users can prompt the model to find references, pull quotes, or locate all mentions of a specific term across the document. When PDFs are stored within a custom GPT or Project, ChatGPT uses retrieval-augmented generation to return the most relevant sections based on meaning, not just exact phrasing. Navigation is entirely prompt-based—users specify a page number, heading, or phrase, and the model responds with the requested excerpt or context in-line. There is no split-screen viewer or clickable page jumping; instead, page numbers are referenced in text responses. The Projects workspace preserves document context between sessions, enabling users to resume searches without re-uploading files.
Claude integrates semantic search, page-level navigation, and a split-pane viewer. Responses always include inline citations with page numbers. Clicking a citation instantly highlights the corresponding section in the left-side document pane, giving users immediate context. Page thumbnails allow for quick scrolling and navigation. Users can ask to jump to, highlight, or compare specific excerpts. In multi-file chats, Claude automatically includes file identifiers (e.g., “Report A, page 45”) in responses, making it easy to distinguish between documents. Cross-document search is built-in, enabling complex comparisons and side-by-side references without manual input or switching files.
Feature | ChatGPT | Claude |
Keyword search | Yes (via prompt) | Yes |
Semantic search / retrieval | Yes (in Projects or custom GPTs) | Yes (default) |
Inline citations with page links | No | Yes, clickable |
Split-screen PDF viewer | No | Yes |
Highlight on page jump | No | Yes |
Cross-document querying | Manual via Projects | Native in multi-file chats or knowledge base |
5. Speed and Performance
ChatGPT
File uploads and initial parsing complete in seconds, even for large PDFs approaching the 512 MB limit. Once uploaded, the document is processed asynchronously—the chat remains usable while the model reads the file. Retrieval is fast for short queries or summaries but may slow slightly with long documents or detailed prompts involving multiple sections. In Projects or with custom GPTs, semantic retrieval is more accurate but may add a delay of several seconds. Token limits—2 million per file—can affect how much of a large PDF is actively used in a response, especially when the conversation grows. No client-side viewer means all outputs are rendered as plain text, with no graphical delay.
Claude
Uploads are near-instant for documents up to the 30 MB chat limit (or 32 MB API limit). Parsing includes OCR and layout recognition, which adds a brief processing step, especially for scanned or image-heavy files. Vision-enabled responses—like asking to analyze a chart or compare layout elements—can take slightly longer than standard Q&A, but remain responsive in typical use. The 100-page visual limit ensures fast in-memory access; longer documents default to text-only parsing. Because Claude stores page previews and supports inline navigation, jumping between sections or re-referencing previous answers is smooth and near-instantaneous.
Feature | ChatGPT | Claude |
Upload speed | Fast (up to 512 MB) | Fast (up to 30–32 MB) |
Parsing time | Immediate for plain text | Slight delay with OCR and layout parsing |
Visual query performance | Limited, available in Enterprise only | Fast for images, charts, and layout |
Token/page processing limits | 2 million tokens per file | 100 pages visual, text beyond that |
Multi-turn response speed | High, with minor delays on long prompts | High, with consistent speed across turns |
6. Context Length and Limitations
ChatGPT processes up to 2 million tokens per file, with additional constraints based on model and subscription tier. GPT-4o handles larger contexts and supports multi-file conversations, but total token usage per interaction is capped—responses that exceed the context window may summarize or omit parts of the file. Free-tier users face stricter token ceilings and lower model capacity. There is no fixed page limit, but extremely long or image-heavy PDFs may lead to truncated responses or require document splitting. Token usage includes both the uploaded content and the ongoing conversation history, so long back-and-forths can reduce usable file length unless restarted or trimmed.
Claude supports up to 200,000 tokens per conversation, making it one of the largest available context windows for PDF processing. It automatically prioritizes the most relevant sections of a document when answering, and it can manage multiple PDFs in a single session. For visual processing, there is a hard limit of 100 pages per file—if the file is longer, Claude reads the remainder as plain text only. When users upload multiple files, Claude distributes context space across them efficiently but may omit details from lower-priority documents if the total size approaches the limit. There is no option to manually adjust token prioritization, but responses adapt dynamically to the latest question.
Feature | ChatGPT | Claude |
Max token limit per file | 2 million tokens | 200,000 tokens per conversation |
Page limit (visual) | None (token-based) | 100 pages per file |
Multi-file handling | Yes (with token impact) | Yes, optimized within token limit |
Adaptability to long documents | Partial; truncation possible | High; compresses and prioritizes data |
Context carried across turns | Yes, with token trade-off | Yes, with smart prioritization |
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