5 MB MKV sample file

An MKV file of exactly 5,242,880 bytes. It is a valid Matroska video file, generated for this site and checked with an independent parser. Use it wherever you need a 5 MB sample, test or dummy MKV file.

sample-mkv-5mb.mkv

5 MB5,242,880 bytes

Download 5 MB MKV

Created in your browser in a few seconds, then checked against the SHA-256 checksum. No sign-up.

Type: video/x-matroska
SHA-256: fca69125b26ef0195efef157db1e9c2911cd91219a95d6b0af97f89602c85d1f
Delivery: Created in your browser. Files of 2 MB and more have no direct URL (why).

What is in this file

2,790 frames (1 min 33 s) of a synthetic test pattern with a frame counter, looping every six seconds, in one H.264 (AVC) video track. The index of key frames comes before the picture data, so a player can seek without reading the whole file. 2,314 bytes of an EBML Void element bring the file to the exact size.

Dimensions	640 × 360 px
Duration	1 min 33 s
Frame rate	30 fps
Video codec	H.264 (AVC), Main profile
Audio	No audio track
Document type	matroska
Clusters	93, one for each key frame
Seek index	Cues element before the first cluster

First bytes of the file

The first 64 bytes of sample-mkv-5mb.mkv as a hex dump: offset, bytes, then the same bytes as text. The MKV signature is 1A 45 DF A3.

00000000  1a 45 df a3 a3 42 86 81 01 42 f7 81 01 42 f2 81  |.E...B...B...B..|
00000010  04 42 f3 81 08 42 82 88 6d 61 74 72 6f 73 6b 61  |.B...B..matroska|
00000020  42 87 81 04 42 85 81 02 18 53 80 67 01 00 00 00  |B...B....S.g....|
00000030  00 4f ff cc 11 4d 9b 74 b3 4d bb 8e 53 ab 84 15  |.O...M.t.M..S...|

Preview

MKV files cannot be shown in a browser. Download the file and open it in an application that reads MKV, such as VLC and mpv.

Where 5 MB matters

A 5,242,880-byte file: the size of a phone photo and the minimum part size for S3 multipart uploads. These are the default limits a file of this size is useful for testing:

System	Limit	Note
PHP	2 MB per uploaded file by default (upload_max_filesize)	A 5 MB upload fails on an untuned PHP installation.
Vercel Functions	4.5 MB request body	Larger uploads must go directly to object storage.
Amazon S3 multipart upload	5 MiB minimum part size	This file is exactly one minimum part.
AWS Lambda	6 MB synchronous invocation payload	5 MB of binary data exceeds it once base64-encoded.
Browser localStorage	About 5 MB per origin	Storing this file as text fills the quota.
Django	2.5 MB in memory by default	Larger uploads are streamed to a temporary file instead of held in memory.

All 5 MB sample files

Use this file for

Testing image resizing and memory use
Verifying type detection between MKV and WebM
Testing media servers and players with a seekable file

Testing notes for MKV

Safari and Firefox do not play MKV, and Chrome does so only for some codecs. Remux to MP4 or WebM before showing video in a page.
A file with no Cues element still plays but cannot seek quickly. Recordings that were interrupted, and live captures, are often like this.

MKV format reference

Technical details

File name	sample-mkv-5mb.mkv
Format	MKV (Matroska video)
Extension	.mkv
MIME type	video/x-matroska
Size	5,242,880 bytes (5 MB)
Kind	Binary
Signature	1A 45 DF A3
SHA-256	fca69125b26ef0195efef157db1e9c2911cd91219a95d6b0af97f89602c85d1f
Created	2026-10-14
Validation	Exact size, signature bytes and structure checked when the generator was built; your copy is checked against the SHA-256 after it is created
Preview	Not available for this file; details only
Source	Generated in your browser by this site's generator; not copied from elsewhere
Licence	Free to use, modify and redistribute (terms)
Category	Video

Validated for expected format and integrity. 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 bytes are the same every time and in every browser, so after saving it you can compare its checksum with the SHA-256 value above.

sha256sum sample-mkv-5mb.mkv     # Linux
shasum -a 256 sample-mkv-5mb.mkv # macOS

On Windows, run Get-FileHash sample-mkv-5mb.mkv -Algorithm SHA256 in PowerShell. For scripts and pipelines, save the file once and keep your own copy, or use a 1 MB file, which has a direct URL.

Related files

Questions about this file

Is this file exactly 5 MB?: Yes. It is 5,242,880 bytes, which is 5 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 5 MB MKV file?: 2,790 frames (1 min 33 s) of a synthetic test pattern with a frame counter, looping every six seconds, in one H.264 (AVC) video track. The index of key frames comes before the picture data, so a player can seek without reading the whole file. 2,303 bytes of an EBML Void element bring the file to the exact size.
Which codec do the MKV samples use?: H.264 video at 640 × 360 and 30 frames per second, with no audio track. The index of key frames is at the front of the file.

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