20 MB VTT sample
A VTT file of exactly 20,971,520 bytes. It is a valid WebVTT subtitles file, generated by this site. Compare its checksum and test it with the parser used by your application. Use it wherever you need a 20 MB sample, test or dummy VTT file.
Download
sample-vtt-20mb.vtt
20 MB20,971,520 bytes
Download 20 MB VTTCreated in your browser in a few seconds, then checked against the SHA-256 checksum. The file is not uploaded anywhere. No sign-up.
- Type
- text/vtt
- SHA-256
5e1e6d7ab5b8d71e5c625f879126ec9521b30b4c9322667e51a967c044abae9d- Delivery
- Created in your browser from static generator assets (how it works).
What is in this file
A WEBVTT header, a note and 175,850 numbered cues, one every 686 ms and each shown for 617 ms. A final NOTE block, which players do not display, brings the file to the exact size.
| Cues | 175,850 |
|---|---|
| Timing | HH:MM:SS.mmm |
| Line length | At most 42 characters |
| Styling | None |
| Encoding | UTF-8 (ASCII characters only) |
| Line endings | LF |
How the file begins
The opening lines of sample-vtt-20mb.vtt, exactly as they appear in the file.
00000000 57 45 42 56 54 54 0a 0a 4e 4f 54 45 20 53 61 6d |WEBVTT..NOTE Sam|
00000010 70 6c 65 54 65 73 74 46 69 6c 65 73 20 73 61 6d |pleTestFiles sam|
00000020 70 6c 65 20 57 65 62 56 54 54 20 66 69 6c 65 20 |ple WebVTT file |
00000030 28 32 30 20 4d 42 29 0a 0a 31 0a 30 30 3a 30 30 |(20 MB)..1.00:00|Preview
Creates the file in your browser and shows the first 64 KB of it.
Where 20 MB matters
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. These are the default limits a file of this size is useful for testing:
| System | Limit | Note |
|---|---|---|
| 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. |
Use this file for
- Finding the first upload limit in a new stack
- Testing accessibility of video players
- Testing HTML video captions
Testing notes for VTT
- Browsers load caption tracks under the same cross-origin rules as scripts, so a .vtt file on another domain needs CORS headers.
- Servers that send WebVTT as text/plain may see tracks ignored; the correct type is text/vtt.
Technical details
| File name | sample-vtt-20mb.vtt |
|---|---|
| Format | VTT (WebVTT subtitles) |
| Extension | .vtt |
| MIME type | text/vtt |
| Size | 20,971,520 bytes (20 MB) |
| Kind | Text |
| Signature | 57 45 42 56 54 54 |
| SHA-256 | 5e1e6d7ab5b8d71e5c625f879126ec9521b30b4c9322667e51a967c044abae9d |
| Created | 2026-10-23 |
| Validation | See the listed size and SHA-256. Small downloads are checked in the browser; verify streamed downloads manually. A hash match does not prove parser compatibility. |
| Preview | Available on this page |
| Source | Generated in your browser by this site's generator; not copied from elsewhere |
| Licence | Free to use, modify and redistribute (terms) |
| Category | Subtitles |
Check the stated structure and checksum against your application requirements. As with any download, scan the file with your own security tools before opening it. How files are made and checked
Verify your copy
This file is created in your browser, so it has no direct URL for curl or wget. The generator is designed to produce reproducible bytes. After saving, compare the checksum with the SHA-256 value above.
sha256sum sample-vtt-20mb.vtt # Linux
shasum -a 256 sample-vtt-20mb.vtt # macOSOn Windows, run Get-FileHash sample-vtt-20mb.vtt -Algorithm SHA256 in PowerShell. For scripts and pipelines, save the file once and keep your own copy.
Related files
Questions about this file
- Is this file exactly 20 MB?
- Yes. It is 20,971,520 bytes, which is 20 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
- What is inside the 20 MB VTT file?
- A WEBVTT header, a note and 175,850 numbered cues, one every 686 ms and each shown for 617 ms. A final NOTE block, which players do not display, brings the file to the exact size.
- Can I use these with the MP4 samples?
- Yes. Add the file with a <track> element to check that captions appear, though the text is unrelated to the picture.