20 MB sample files
A 20,971,520-byte file: right at the default attachment limit of Outlook, and just under the 25 MB ceilings of Gmail and GitHub web uploads. Available in 6 formats.
Download a 20 MB file
Each file is exactly 20,971,520 bytes and is a valid file of its format. Any of them works as a 20 MB dummy file or test file.
| File | Format | Size | Contents | Download |
|---|---|---|---|---|
| 20 MB PDF samplesample-pdf-20mb.pdf | 20 MB20,971,520 bytes | Pages: 16 | Download PDF | |
| 20 MB TXT samplesample-txt-20mb.txt | TXT | 20 MB20,971,520 bytes | Numbered lines: 210,979 | Download TXT |
| 20 MB CSV samplesample-csv-20mb.csv | CSV | 20 MB20,971,520 bytes | Data rows: 154,320 | Download CSV |
| 20 MB ZIP samplesample-zip-20mb.zip | ZIP | 20 MB20,971,520 bytes | Entries: 4 | Download ZIP |
| 20 MB BIN samplesample-bin-20mb.bin | BIN | 20 MB20,971,520 bytes | Pseudo-random bytes | Download BIN |
| 20 MB MP4 samplesample-mp4-20mb.mp4 | MP4 | 20 MB20,971,520 bytes | 640 × 360 px | Download MP4 |
What is a 20 MB test file?
Twenty megabytes is where email gives up. Outlook refuses attachments above 20 MB for internet mail accounts by default, and Gmail stops at 25 MB per message, so a 20 MB file tests the edge of what can still be sent as an attachment.
The same range holds a cluster of 25 MiB limits on developer platforms: files added to a GitHub repository through the browser, and assets on static hosts such as Cloudflare Pages. A 20 MB file is the largest round size that still fits under all of them.
In everyday terms: About two minutes of CD-quality WAV audio, or a short clip of 1080p video.
Limits near 20 MB
Default limits in widely used software that a 20 MB file is useful for testing. Defaults change between versions, so confirm them in the documentation for the version you run.
| System | Limit | What happens at 20 MB |
|---|---|---|
| Microsoft Outlook | 20 MB of attachments by default for internet mail accounts | This file is right at the limit; add a second attachment and it is exceeded. |
| Gmail | 25 MB per message | Under the limit, although email encoding adds about a third in transit. |
| GitHub web uploads | 25 MiB per file added through the browser | Accepted. Pushing with Git allows larger files. |
| Cloudflare Pages assets | 25 MiB per file | The largest round size that can be served as a static asset. |
| Amazon API Gateway | 10 MB payload | Rejected; the upload has to go directly to object storage. |
| ASP.NET Core (Kestrel) | About 28.6 MB request body by default | Accepted with room for the multipart overhead. |
Good for
- Testing email attachment limits
- Checking uploads just under a 25 MB cap
- Exercising chunked and resumable uploads
- Timeout and retry tests on slower connections
Transfer time
How long 20,971,520 bytes take to move, before any compression.
| 1 Mbit/s (slow mobile or uplink) | 2 min 48 s |
|---|---|
| 10 Mbit/s (basic broadband) | 17 seconds |
| 100 Mbit/s (fast broadband) | 1.7 seconds |
Related
Next sizes: 10 MB sample files.
20 MB files: questions
- How long does a 20 MB download take?
- About 17 seconds at 10 Mbit/s and under 2 seconds at 100 Mbit/s. On a 1 Mbit/s uplink the same upload takes nearly three minutes.
- How many bytes is 20 MB?
- 20 MB is 20,971,520 bytes on this site. Sizes use binary units, in which 1 KB is 1,024 bytes and 1 MB is 1,048,576 bytes.