Anthropic PDF rejected: 32 MB, 600 pages, no passwords, standard format only

TL;DR

Remove passwords or encryption before sending; convert nonstandard PDFs to standard ones. Enable prompt caching on repeated analysis of the same document.

Steps

1. Check three things: total request size against 32 MB (the whole payload counts, not just the PDF), page count against 600 pages (100 when the request's context window is under 1M tokens), and whether the PDF has a password or encryption, which is not supported. Encrypted or nonstandard PDFs are the silent killer when size and pages look fine.
2. Split oversized PDFs into chunks under the limits.
3. Upload with the Files API and reference the returned file_id in document blocks to keep payloads small, especially for repeated analysis of the same file.
4. Remove passwords or encryption before sending; convert nonstandard PDFs to standard ones.
5. Enable prompt caching on repeated analysis of the same document.

When to use

You are seeing this: The request fails when a PDF is attached: 400 on the document block or 413 on the request. Use this skill when you run into "Anthropic PDF rejected: 32 MB, 600 pages, no passwords, standard format only".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

Check three things: total request size against 32 MB (the whole payload counts, not just the PDF), page count against 600 pages (100 when the request's context window is under 1M tokens), and whether the PDF has a password or encryption, which is not supported.

PDF requirements (32 MB, 600 pages / 100 under 1M context, standard unencrypted PDFs) and the three delivery methods (URL, base64, Files API file_id) are documented on the PDF support page. Verified live at https://docs.anthropic.com/en/docs/build-with-claude/pdf-support.