500 KB VTT sample

A VTT file of exactly 512,000 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 500 KB sample, test or dummy VTT file.

sample-vtt-500kb.vtt

500 KB512,000 bytes

Download 500 KB 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: 78df1add6157dc48f02a50b1486dad7bdb6a01256daa71233cca9319916d94d6
Delivery: Created in your browser from static generator assets (how it works).

What is in this file

A WEBVTT header, a note and 4,354 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.

Cues	4,354
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-500kb.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 35 30 30 20 4b 42 29  0a 0a 31 0a 30 30 3a 30 |(500 KB)..1.00:0|

Preview

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

Where 500 KB matters

A 512,000-byte file: larger than most API body limits, smaller than most upload limits. These are the default limits a file of this size is useful for testing:

System	Limit	Note
Amazon DynamoDB items	400 KB per item	500 KB cannot be stored as a single item.
Express body parsers	100 KB by default	Rejected unless the limit is raised.
nginx request body	1 MB by default (client_max_body_size)	Accepted with room to spare.

All 500 KB sample files

Use this file for

Checking email size handling
Testing accessibility of video players
Testing HTML video captions

Testing notes for VTT

Servers that send WebVTT as text/plain may see tracks ignored; the correct type is text/vtt.
Browsers load caption tracks under the same cross-origin rules as scripts, so a .vtt file on another domain needs CORS headers.

VTT format reference

Technical details

File name	sample-vtt-500kb.vtt
Format	VTT (WebVTT subtitles)
Extension	.vtt
MIME type	text/vtt
Size	512,000 bytes (500 KB)
Kind	Text
Signature	57 45 42 56 54 54
SHA-256	78df1add6157dc48f02a50b1486dad7bdb6a01256daa71233cca9319916d94d6
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-500kb.vtt     # Linux
shasum -a 256 sample-vtt-500kb.vtt # macOS

On Windows, run Get-FileHash sample-vtt-500kb.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 500 KB?: Yes. It is 512,000 bytes, which is 500 KB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 500 KB VTT file?: A WEBVTT header, a note and 4,354 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.

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