Verified against Anthropic documentation · July 23, 2026
Claude supports many common document and image types, but chat uploads and project files have different limits. A file can fail even when its extension is supported, so first identify where you are uploading it.
Supported Claude document types
Anthropic currently lists PDF, DOCX, CSV, TXT, HTML, ODT, RTF, EPUB, JSON, and XLSX for documents, plus JPEG, PNG, GIF, and WebP for images. XLSX upload requires code execution and file creation to be enabled for the account.
| Limit | Current official value |
|---|---|
| File uploaded to a chat | 500 MB per file |
| Files in one chat | Up to 20 |
| File added to a Project | 30 MB per file |
| Project file count | No fixed count, but total content must fit the context window |
| Image dimensions | Up to 8000 × 8000 pixels |
| Visual PDF analysis | PDF under 100 pages with a supported multimodal Claude model |
1. Check whether it is a chat upload or a Project file
Anthropic currently allows up to 500 MB per file in a chat, but files added to a Project are limited to 30 MB each. Email clients and cloud drives may show a rounded value, so inspect the file properties on the device. Compress images, remove unnecessary embedded media, or export a smaller PDF when the file is close to the relevant limit.
2. Count every file in the chat
Claude allows up to 20 files in a chat. Files added earlier in the same conversation still count. Start a new chat or combine related documents when the current conversation has reached the limit.
3. Convert an unsupported or troublesome format
- Export Apple Pages or another proprietary document to DOCX or PDF.
- Save structured data as CSV or JSON.
- Convert a scanned document to a searchable PDF if text extraction is needed.
- Export a complex spreadsheet to CSV when formulas and formatting are not required.
- Remove password protection before uploading, if you are authorized to do so.
4. Enable code execution for XLSX files
Anthropic says XLSX support depends on code execution and file creation. If an Excel file fails while CSV works, check whether that capability is available and enabled for the active Claude account or workspace.
5. Know what Claude can see inside a document
For non-PDF documents, Anthropic says Claude extracts text but does not read embedded images. A DOCX file may upload successfully while charts and screenshots inside it remain unavailable to the model. Upload the important images separately or convert the document to an appropriate PDF.
6. Split long or image-heavy PDFs
Supported multimodal Claude models can analyze text and visual elements in PDFs under 100 pages. Larger PDFs and extracted content can be subject to additional processing limits, so divide a long report into chapters and ask focused questions about one section at a time when visual analysis matters.
7. Rule out an account or service issue
- Try one small TXT file in a new chat.
- Confirm the intended Claude account and workspace are active.
- Check Anthropic’s service-status page.
- Try a current browser without an aggressive upload-blocking extension.
- If the problem persists, record the time, timezone, browser/app, and exact error for support.
Privacy check before uploading
Only upload a file when you have permission to share its contents. Remove secrets, customer data, credentials, health information, and other unnecessary personal information before sending a document to any AI service.
Official sources
HiseHub is independent and is not affiliated with Anthropic. File support and limits can change.