3 MB VTT sample

A VTT file of exactly 3,145,728 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 3 MB sample, test or dummy VTT file.

Download

sample-vtt-3mb.vtt

3 MB3,145,728 bytes

Download 3 MB VTT

Created 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
2fc459169f33e5f4a93f6d191636b16b9c18e83ba84aa769c11680bd96bb4063
Delivery
Created in your browser from static generator assets (how it works).

What is in this file

A WEBVTT header, a note and 26,560 numbered cues, one per second and each shown for 0.9 s. A final NOTE block, which players do not display, brings the file to the exact size.

Cues26,560
TimingHH:MM:SS.mmm
Line lengthAt most 42 characters
StylingNone
EncodingUTF-8 (ASCII characters only)
Line endingsLF

How the file begins

The opening lines of sample-vtt-3mb.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 33 20 4d 42 29 0a 0a  31 0a 30 30 3a 30 30 3a |(3 MB)..1.00:00:|

Preview

Creates the file in your browser and shows the first 64 KB of it.

Where 3 MB matters

A 3,145,728-byte file, 3 MB in the binary units that operating systems and upload limits use. It is useful wherever a form, an API gateway, a storage quota or a mail server is configured with a limit of about this size.

All 3 MB sample files

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.

VTT format reference

Technical details

File namesample-vtt-3mb.vtt
FormatVTT (WebVTT subtitles)
Extension.vtt
MIME typetext/vtt
Size3,145,728 bytes (3 MB)
KindText
Signature57 45 42 56 54 54
SHA-2562fc459169f33e5f4a93f6d191636b16b9c18e83ba84aa769c11680bd96bb4063
Created2026-10-23
ValidationSee 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.
PreviewAvailable on this page
SourceGenerated in your browser by this site's generator; not copied from elsewhere
LicenceFree to use, modify and redistribute (terms)
CategorySubtitles

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-3mb.vtt     # Linux
shasum -a 256 sample-vtt-3mb.vtt # macOS

On Windows, run Get-FileHash sample-vtt-3mb.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 3 MB?
Yes. It is 3,145,728 bytes, which is 3 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 3 MB VTT file?
A WEBVTT header, a note and 26,560 numbered cues, one per second and each shown for 0.9 s. 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.