Claude file upload limits and supported formats in 2025
- Graziano Stefanelli
- Aug 15
- 3 min read
Claude allows users to upload a range of documents, images, and other file types for analysis, but each session is governed by strict size and quantity limits.
The file handling system in Claude is designed to balance speed with context management. Individual uploads must stay under fixed size thresholds, and there are limits on how many files can be attached to a single conversation. These constraints apply across free and paid plans, although higher tiers offer longer context windows and greater throughput. Understanding these limits helps avoid wasted uploads and ensures smoother interaction.
File uploads are capped by both size and quantity.
In any chat, Claude accepts a maximum of 20 files, with each file limited to 30 MB. This ceiling applies regardless of plan tier. The restriction is enforced at the upload stage, meaning larger files must be reduced or split before submission.
Within projects, the system technically allows unlimited files, but the combined extracted text must remain within the model’s context window of roughly 200,000 tokens. This constraint determines how much of the uploaded material can be referenced in a single response.
File quantity and size rules
Context | Max files | Max file size | Context limit |
Chat | 20 | 30 MB | Based on chat memory |
Project | Unlimited | 30 MB | ≈ 200k tokens total |
Document formats are widely supported.
Claude can process most common document types, including PDF, DOCX, TXT, RTF, ODT, HTML, EPUB, JSON, and CSV. Spreadsheet support extends to XLSX files when the “Analysis Tool” option is active, allowing direct table parsing. For CSVs, no additional tool setting is required.
When working with PDFs, the system focuses on text content. Embedded images or scanned pages are not read unless the file is prepared as a multimodal PDF compatible with Claude’s visual models.
Supported document formats
Format type | Examples | Notes |
Text-based | TXT, RTF, DOCX, ODT, HTML, EPUB | Direct text extraction |
Tabular | CSV, XLSX | XLSX requires Analysis Tool enabled |
Structured | JSON | Parsed as raw structured data |
Text only unless multimodal PDF is used |
Images are accepted in multiple formats and resolutions.
Claude supports JPEG, PNG, GIF, and WEBP images. The recommended resolution for best analysis is at least 1,000 × 1,000 pixels, and the system can handle images up to around 8,000 × 8,000 pixels. Lower resolution files are still accepted but may reduce recognition accuracy.
Image uploads are counted toward the same 20-file chat limit as documents, and each is subject to the 30 MB cap. In projects, images are stored alongside documents and contribute to the overall token count once processed.
Audio files can be transcribed inside projects.
MP3 and WAV files can be uploaded for transcription within project workspaces. The same 30 MB file size limit applies, and the resulting text is added to the project’s context pool. Audio upload is not available in quick chat mode; it requires a project environment to function.
Usage quotas depend on plan tier and attachment type.
In the free tier, Claude permits roughly 20–30 messages per day when attachments are included. The limit is daily and resets automatically. The Pro tier raises this to about 45 messages every five hours, but message length and file size affect the count. Larger attachments consume more of the quota because they occupy more processing capacity.
Plan-based usage overview
Plan | Messages with attachments | Reset cycle | Priority |
Free | ~20–30 per day | Daily | Standard |
Pro | ~45 every 5 hours | 5-hour window | Higher |
Working within Claude’s limits improves speed and accuracy.
To make the most of Claude’s file capabilities:
Compress or split large PDFs and datasets before upload.
Use clean, searchable PDFs for better extraction accuracy.
For spreadsheets, prefer CSV unless XLSX features are essential.
Resize large images to meet recommended resolution without exceeding size limits.
Upload only the necessary files to keep the context window focused.
Claude’s file handling system is flexible but bound by fixed ceilings. Knowing the accepted formats, size restrictions, and plan-specific quotas allows you to prepare inputs that process quickly and yield more accurate results. This planning avoids mid-session interruptions and makes complex document and media analysis smoother from start to finish.
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