Claude’s file-too-large error needs a check of the file and upload destination, not a longer prompt. Start by recording the exact error, file format, size and page count. Then check whether you are attaching it to a chat or adding it to a project’s Files section. Those destinations have different limits. A file that uploads successfully can also contain more text than the conversation can use.
On this page
Check these limits first
Anthropic’s upload guidance, dated July 23, 2026, lists these limits:
| Destination | Published limit |
|---|---|
| Chat | 500 MB per file; up to 20 files per chat |
| Project Files | 30 MB per file; combined content must fit the context window |
| Maximum 1,000 pages | |
| Image | Maximum 8,000 × 8,000 pixels |
A PDF above 1,000 pages produces the named error. PDFs of up to 100 pages support text and visual analysis; longer supported PDFs are processed as text only. Non-PDF documents have text extracted, so embedded pictures are not interpreted. XLSX uploads require code execution and file creation to be enabled.
The supported document list includes PDF, DOCX, CSV, TXT, HTML, ODT, RTF, EPUB, JSON and XLSX. Images can be JPEG, PNG, GIF or WebP. These product details were checked on October 23, 2026.
Keep a recovery copy before changing anything
Work on a duplicate of the original document. Give the duplicate a name that identifies the section, such as supplier-report-pages-40-65.pdf. Keep a note of which original pages it contains, especially when the report’s printed page numbers differ from the PDF viewer.
Splitting a document can remove context. If a table refers to a definition in another chapter, include that definition with the table. If you need a comparison across chapters, decide which sections are required before choosing the split points.
This is a preparation workflow, not a promise that any particular file will be accepted. Check the reduced file’s actual size and page count after saving it.
Upload the section that answers the question
For a long report, start with the question you need answered. A request to compare two policies needs those policies and their definitions; it may not need the report’s appendices. A request to interpret a chart needs the chart and its explanatory notes.
A useful instruction for a deliberately selected extract is:
This file contains pages [range] from [document title].
Answer this question using only this extract: [question].
For each factual answer, give the PDF viewer page number.
If the extract lacks the necessary context, identify what is missing.
This is an original template for controlling scope. It has not been tested against a particular document. Replace the brackets with real details and verify every answer against the original.
Separate an upload problem from a reading problem
If the attachment is rejected, changing the question cannot reduce its bytes or pages. Correct the file or destination first. If the attachment is accepted but the answer misses a chart, inspect whether the upload route supports that visual content.
For text-heavy work, an extract may be easier to review than an entire archive. For visual work, preserve the relevant page rather than assuming that copying its words also preserves its meaning.
Claude’s usage allowance and conversation-length limit are separate topics. Read usage versus length limits if the message concerns the conversation rather than this file.
