Claude File Upload Limit: Size & Count Caps (2026)
Claude limits uploads by per-file size, how many files and images you can attach at once, and how many pages a PDF can hold. As of 2026, individual files are capped at roughly 30MB each, with a limited number of files and images per chat, and PDFs bound by a page count as well as size. Projects and knowledge bases have their own, larger capacity for reference documents. These figures change often, so treat them as a snapshot.
The Limits at a Glance (as of 2026)
Per-file size
- Up to roughly 30MB per file in the Claude apps
- Images capped lower in practice (a handful of MB each)
Per-chat attachments
- A limited number of files per message/conversation (single digits to ~20)
- A handful of images per message
PDFs
- Bound by page count as well as size — very long PDFs may be truncated or need splitting
Projects / knowledge
- A much larger pooled capacity for reference documents, measured against the project’s context budget
Anthropic adjusts these limits over time, and exact numbers differ between the web/desktop apps, mobile, and the API. Always confirm against Anthropic’s current help center before relying on a specific figure.
Supported Formats and What Claude Does With Them
Claude accepts common document and image types — PDF, plain text, Word docs, spreadsheets/CSV, and images (PNG, JPEG, and similar). For text-based files it reads the content into context; for PDFs it can read both the text and, on capable models, the visual layout of pages. Images are analyzed directly, which is why they carry tighter size and count limits than text files.
If Claude refuses a file, it’s usually because the file exceeds the size cap, is an unsupported format, or — for PDFs — has too many pages to ingest in one pass.
Why PDFs Have a Page Limit On Top of Size
A PDF can be well under the 30MB size cap and still be too long. Claude reads PDFs into its context window, and every page consumes tokens (more so when it processes page images, not just extracted text). So a long PDF can hit the context/page ceiling before it hits the file-size ceiling. For very long documents, split them into sections and upload the parts you actually need, or paste the relevant text directly.
Chats vs Projects: Two Different Budgets
There are two places to put documents in Claude, with different capacities:
- In a chat — files attached to a single conversation are the tightest budget: a limited number of files and images, each under the size cap, all competing for the conversation’s context.
- In a Project (or knowledge base) — a much larger pooled capacity meant for reference material you’ll reuse across chats. Claude retrieves from it as needed rather than loading everything into every message, so it holds far more than a single chat.
If you keep re-uploading the same reference docs, put them in a Project once instead of attaching them to each chat.
How to Work Within Claude’s File Limits
- Split large files into focused sections rather than uploading one giant document.
- Crop images tightly to the region that matters so downscaling doesn’t blur fine detail.
- Use Projects for reference material you reuse, keeping individual chats lean.
- Paste short excerpts directly when you only need a few pages of a long PDF.
Troubleshooting
What is the maximum file size for Claude?
Around 30MB per file in the Claude apps as of 2026, with images capped lower in practice. Confirm current values in Anthropic’s help center.
Why won’t Claude accept my PDF?
Usually because it exceeds the size cap, has too many pages to fit the context window, or is an unsupported format. Split long PDFs into sections and upload only what you need.
How many files can I attach to one Claude chat?
A limited number per conversation — from single digits up to around 20, each under the size cap. For large reference sets, use a Project instead.
What file formats does Claude support?
Common ones: PDF, plain text, Word docs, spreadsheets/CSV, and images (PNG, JPEG, and similar). Text is read into context; images are analyzed directly.
How is a Project different from attaching files to a chat?
A Project offers a much larger pooled capacity for reference documents that Claude retrieves as needed, whereas chat attachments share one conversation’s tighter context budget.
Quick Reference
| Limit type | Approximate cap (2026) |
|---|---|
| Per-file size | ~30MB |
| Images per message | A handful |
| Files per chat | Single digits to ~20 |
| PDF ceiling | By page count + size |
| Project/knowledge | Much larger pooled capacity |
Figures as of 2026 and subject to frequent change.
If you’d rather have an AI that works directly in your inbox — pulling attachments, reading them, and acting on triggers — than one you upload files into by hand, an assistant like Carly runs from your email. See the best AI email agents.
Related guides: Claude usage limit · ChatGPT file upload limit · Claude vs Carly · ChatGPT Plus limits · Cursor usage limits · DeepSeek limits · Discord character limit
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