20 MB MP4 test file
A MP4 video of exactly 20,971,520 bytes, created instantly in your browser. Nothing is uploaded, and there is no sign-up.
Testing a limit? Grab the edge cases too
Need another size or name? Open it in the generator.
What’s inside the file
A minimal MP4 container (ftyp + mdat boxes) at the exact size. It is detected as video/mp4 but does not play — it is built for upload and size tests.
- Size: 20,971,520 bytes = 20 MB (binary) ≈ 20.97 MB (decimal)
- MIME type:
video/mp4 - File name:
dummy-20mb.mp4
Will a 20 MB file upload?
How a 20 MB file compares with published limits (verified 2026-09-27):
| Service | Limit | 20 MB file |
|---|---|---|
| Gmail — email attachments (total per message) | 25 MB | Fits |
| Outlook.com — email attachments | 25 MB | Fits |
| Yahoo Mail — email attachments (total per message) | 25 MB | Fits |
| WhatsApp — documents / files | 2 GB | Fits |
| Discord (free) — file attachments | 20 MB | Fits |
| Slack — file upload | 1 GB | Fits |
| Facebook Messenger — files in chats | 100 MB | Fits |
| Notion (Free) — file upload | 5 MB | Too big |
| Trello (Free) — card attachment from computer | 10 MB | Too big |
| X (Twitter) — image | 5 MB | Too big |
| LinkedIn — document post (pdf, docx, pptx) | 100 MB | Fits |
| Shopify — product image | 20 MB | Fits |
| Typeform — file upload question | 10 MB | Too big |
Sources and 40+ more limits (servers, frameworks, cloud storage): file upload limits reference.
Good for testing
- Video upload size limits
- Chunked / resumable upload testing
- Timeouts on slow connections
Questions
Is this 20 MB MP4 exactly 20,971,520 bytes?
Yes. The file is exactly 20,971,520 bytes (20 MB with 1 MB = 1,024 × 1,024 bytes). If the system you test counts 1 MB as 1,000,000 bytes, use the 20,000,000-byte button instead.
Will the MP4 file play?
No — A minimal MP4 container (ftyp + mdat boxes) at the exact size. It is detected as video/mp4 but does not play — it is built for upload and size tests. Use it to test uploads, size limits and MIME checks, not playback.
Is it safe? Where does the file come from?
The file is created by JavaScript in your own browser when you click the button. Nothing is uploaded or downloaded from a server, and the file contains no macros, scripts or personal data.
More about the format: MP4 format guide.