Verified against xAI documentation · July 27, 2026
Grok file upload failed? Start by checking the size, format, platform, and chat. Grok accepts documents, spreadsheets, code, images, audio, and video, but a supported extension does not guarantee that every upload will work on every platform. Most files can be up to 150 MB. The web app supports the largest batches, while mobile apps have lower or less specific file-count limits.
Grok file upload limits at a glance
| Upload rule | Current xAI guidance |
|---|---|
| Most files | Up to 150 MB per file |
| Files in one web upload | Up to about 100 files |
| Files in one Android upload | Up to 20 files |
| Files in one iOS upload | Multiple files are supported; xAI does not publish one fixed number |
| Large PDFs | Grok may focus on text and key visuals; xAI recommends referring to actual page numbers |
| Platform differences | The web app generally has broader document support |
These are consumer Grok limits for grok.com and the iOS and Android apps. Limits can vary by platform or subscription and may change as xAI updates the product.
Which file types does Grok support?
xAI currently documents broad support across the following groups:
- Documents and data: PDF, DOCX, TXT, CSV, XLSX, PPTX, HTML, XML, JSON, Markdown, LaTeX, ODT, and RTF.
- Code: common source files such as PY, CPP, JAVA, HTML, and CSS.
- Images: JPEG, PNG, WebP, HEIC, and BMP. GIF and SVG support can vary by platform.
- Audio: MP3, WAV, M4A, OGG, FLAC, and AAC.
- Video: MP4 and MOV.
A file can still fail because of its internal encoding, corruption, password protection, unusual embedded media, or a temporary app problem. Treat the extension as the first check, not the final diagnosis.
1. Check the actual file size
Open the file properties on your device instead of relying on an email attachment preview or a rounded cloud-drive value. If the file is close to 150 MB, create a smaller copy before trying again.
- Compress or split a long PDF.
- Export a spreadsheet without unnecessary images or hidden sheets.
- Reduce image resolution when pixel-level inspection is not required.
- Trim audio or video to the relevant section.
- Remove embedded media from a presentation and upload it separately.
2. Reduce the number of files
The Grok web app can accept much larger batches than Android. If a mobile upload fails, try one file first. Then add the remaining files in smaller groups or move the task to grok.com. A batch of individually valid files can still fail when the total upload is too large or the connection is unstable.
3. Convert a troublesome format
When Grok reports that a file type is unsupported, convert it to a simpler documented format:
- Export Apple Pages or another proprietary document to DOCX or PDF.
- Save spreadsheet data as CSV when formulas and formatting are not important.
- Convert a scanned document to a searchable PDF when you need text extraction.
- Use PNG or JPEG when GIF or SVG behaves differently between platforms.
- Convert an uncommon audio or video container to MP3 or MP4.
Only remove encryption or password protection when you own the file or have permission to do so.
4. Test a small file in a new chat
Create a new conversation and upload one small TXT or PDF file. This separates a general upload problem from a file-specific or conversation-specific problem.
- If the small file works, the original file or batch is the likely cause.
- If it fails only in the mobile app, update the app and test grok.com.
- If it fails everywhere, sign out and back in, then check whether Grok is experiencing a service issue.
5. Give Grok focused instructions for large PDFs
xAI says Grok handles long PDFs by focusing on text and key visuals. For documents over roughly 100 pages, split the file into logical sections when possible. Ask about a named chapter, table, or actual printed page number instead of requesting a complete analysis in one prompt.
A useful prompt is: “Read pages 42–58. Extract the assumptions, list every figure cited, and flag any conclusion that is not supported by those pages.”
6. Upload important images separately
xAI notes that embedded images inside non-PDF documents may not be processed visually. A DOCX or PPTX can upload successfully while a chart or screenshot inside it is missed. Export the important chart as PNG, or convert the whole document to PDF when visual layout matters.
7. Rule out a browser, app, or network problem
- Update the Grok app or use a current desktop browser.
- Disable an aggressive content blocker for one test.
- Avoid switching networks while the file is uploading.
- Try the web app when a format fails only on iOS or Android.
- Record the exact message, time, platform, file type, and file size before contacting support.
8. Remove old files when storage is the problem
On the web, xAI directs users to grok.com/files to manage uploaded content. Delete files you no longer need, then retry with one small attachment. Deleting old files will not repair a corrupted document, but it can rule out an account-storage problem.
Fast diagnosis checklist
| What happens | Best next step |
|---|---|
| “File type not supported” | Convert to PDF, DOCX, TXT, CSV, PNG, JPEG, MP3, or MP4 |
| “Tap to retry” or upload stops | Try one smaller file and a stable connection |
| Attachment cannot be loaded | Switch platform or convert the file |
| Mobile fails but web works | Use grok.com for the larger or less common format |
| Upload succeeds but content is missed | Upload key images separately and ask about specific pages |
| Every file fails | Test a new chat, update the app, sign in again, and check service availability |
Privacy check before uploading
Only upload material you are allowed to share. Remove passwords, API keys, private customer data, medical information, financial records, and unnecessary personal identifiers. For confidential work, review the account’s data controls and your organization’s AI policy before sending a file.
Official sources
HiseHub is independent and is not affiliated with xAI or X. File support and limits can change.