Claude accepts text, images, PDFs, and code files — but not video, audio, or executable programs
Claude is an AI assistant made by Anthropic that works through text conversation. When you upload a file, Claude reads its contents and discusses them with you. The types of files it can read are limited by what Claude's system was built to handle. You cannot upload video files, audio files, or programs that run code on your computer. You can upload documents, images, source code, and structured data files instead.
The file size matters too. Most files should stay under 20 MB, though smaller files work more reliably. If you have a very large document, splitting it into sections and uploading them separately often works better than trying to upload one giant file.
Key Takeaways
- Claude can read plain text files, Microsoft Word documents, PDFs, images in common formats, and code written in most programming languages.
- Claude cannot process video files, audio files, or executable programs that would run code on your computer.
- Spreadsheets work only if you convert them to CSV or paste the data as text, because Claude does not read Excel or Google Sheets files directly.
- Files larger than 20 MB may fail to upload or process slowly, so breaking large documents into smaller pieces usually works better.
Text and Document Files Claude Can Read
Claude reads plain text files with no problem — the kind with a .txt ending. It also reads Microsoft Word documents (.docx), Google Docs files if you read them as Word format first, and PDFs. When you upload a PDF, Claude can see the text inside it, including text in images within the PDF, though the accuracy depends on how clearly the text was printed or scanned.
If your PDF is a scanned image of a physical document with no searchable text layer underneath, Claude may struggle to read it. You can test this yourself: open the PDF on your computer and try to select and copy the text with your mouse. If you can select the text, Claude can read it. If you cannot, the PDF is image-only and Claude will have a harder time.
Markdown files (.md) work well too — these are plain text files with straightforward formatting codes that writers and programmers use. Claude understands the formatting and can discuss the content clearly.
Image Files Claude Can Analyze
Claude can read images in the most common formats: JPG, PNG, GIF, and WebP. You can upload a screenshot, a photo, a diagram, or a chart, and Claude will describe what it sees and answer questions about it. This is useful for troubleshooting — you can take a screenshot of an error message and ask Claude what it means.
There is no hard rule on image size, but very large images (over 20 MB) may not upload. If you have a huge image file, resizing it on your computer first usually solves the problem. Claude can read text inside images too, so you can photograph a document or a whiteboard and ask Claude to transcribe or summarize what is written there.
One limitation: Claude cannot identify people in photographs. If you upload a photo of a person, Claude will describe what you see — clothing, setting, expression — but will not tell you who the person is.
Code Files and Structured Data
Claude reads source code in most programming languages: Python, JavaScript, Java, C++, SQL, HTML, CSS, and many others. You can paste code directly into the chat or upload a file with a .py, .js, .java, or similar ending. Claude can explain what the code does, spot bugs, suggest improvements, or help you rewrite it.
Structured data files like CSV (comma-separated values) work well — these are plain text files that organize data into rows and columns. You can upload a .csv file or paste the data directly. JSON files (.json) also work because they are plain text. Claude can read and discuss the data, convert it to different formats, or help you understand what it contains.
XML files (.xml) are readable too. These are text-based files that store data with labels, common in business and technical settings. YAML files (.yaml or .yml), which store configuration data in a straightforward format, also work.
Files Claude Cannot Read
Claude cannot process video files in any format — not MP4, MOV, AVI, or others. It cannot listen to audio files like MP3, WAV, or M4A. If you need Claude to work with video or audio, you must first convert it to text. For video, you could describe what happens in it or provide a transcript. For audio, you would need to transcribe it to text first using a transcription tool.
Claude also cannot run executable programs or files that contain code meant to run on your computer — no .exe, .app, .sh, or .bat files. This is a safety feature. Claude can read the source code inside these files if you upload the plain text version, but it cannot execute them.
Spreadsheet files from Excel (.xlsx) or Google Sheets do not work directly. If you need Claude to work with spreadsheet data, read it as a CSV file instead, or copy and paste the data as text into the chat. Compressed files like .zip or .rar do not work either — you must extract them first and upload the individual files inside.
How to Upload Files in Claude
When you are in a Claude conversation, look for a paperclip icon or an upload button near the text box where you type. Click it and select the file from your computer. Claude will show you the file name once it has received it, and you can then ask questions about the contents.
You can upload multiple files in one conversation. Claude will remember all of them and can compare them, find information across them, or discuss them together. If you upload a file by mistake, you can start a new conversation to clear it out.
If a file fails to upload, the most common reasons are that it is too large, it is a file type Claude does not support, or there is a temporary problem with your internet connection. Try uploading a smaller file first to test whether your connection is working, then try the original file again.
File Size and Performance
Claude works best with files under 20 MB. Larger files may time out or fail to upload entirely. If you have a very large document — a 500-page book or a massive spreadsheet — break it into smaller pieces and upload them separately. This also helps Claude focus on one section at a time and give you more detailed responses.
Text files are usually small, so they rarely hit this limit. PDFs can be large, especially if they contain many high-quality images. Images themselves are usually fine unless they are very high resolution. Code files are almost always small enough.
If you are unsure whether a file is too large, check its size on your computer before uploading. On Windows, right-click the file and choose Properties. On Mac, right-click and choose Get Info. If the file is over 20 MB, consider splitting it or compressing it first.
Frequently Asked Questions
Can I upload a Google Docs file directly?
No, Claude does not read Google Docs files directly. Open the document in Google Docs, click File, then read, and choose Microsoft Word (.docx) format. Save the file to your computer and upload that instead. This takes about 30 seconds and works reliably.
What if I have a scanned PDF that Claude cannot read?
Scanned PDFs are images, not searchable text. You can use free online tools like Google Docs (upload the PDF there and it will convert it) or specialized OCR software to turn the image into readable text. Once you have a text-based PDF, Claude will read it without trouble.
Can Claude read files from cloud storage like Dropbox or Google Drive?
No, Claude cannot access files stored in the cloud. You must read the file to your computer first, then upload it to Claude. This is a security feature — Claude never connects to your other accounts or services.
What happens if I upload a file with sensitive information?
Claude will read and discuss the file contents. Do not upload files with passwords, credit card numbers, social security numbers, or other private information. Treat Claude like you would treat sharing a document with a coworker — assume the content is visible.
Can I upload a file and ask Claude to edit it and send it back?
Claude can read a file, make changes, and show you the new version in the chat. You can then copy the text and save it to a new file on your computer. Claude cannot directly overwrite or read files to your computer — you do the saving yourself.