25 MB BMP sample

A BMP file of exactly 26,214,400 bytes. It is a valid Windows bitmap file, generated by this site. Compare its checksum and test it with the parser used by your application. Use it wherever you need a 25 MB sample, test or dummy BMP file.

sample-bmp-25mb.bmp

25 MB26,214,400 bytes

Download 25 MB BMP

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

Type: image/bmp
SHA-256: d28362e52271035522a534453c2dd46ee7f099d53a70d57c0bbe5f2fc9007073
Delivery: Created in your browser from static generator assets (how it works).

What is in this file

An uncompressed 3418 × 2556 test card. 10 bytes of unused space between the header and the pixel array bring the file to the exact size.

Dimensions	3,418 × 2,556 px
Bit depth	24-bit RGB
Compression	None (BI_RGB)
Header	BITMAPINFOHEADER (40 bytes)
Row order	Bottom-up

First bytes of the file

The first 64 bytes of sample-bmp-25mb.bmp as a hex dump: offset, bytes, then the same bytes as text. The BMP signature is 42 4D.

00000000  42 4d 00 00 90 01 00 00  00 00 40 00 00 00 28 00 |BM........@...(.|
00000010  00 00 5a 0d 00 00 fc 09  00 00 01 00 18 00 00 00 |..Z.............|
00000020  00 00 c0 ff 8f 01 13 0b  00 00 13 0b 00 00 00 00 |................|
00000030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 |................|

Preview

Creates the file in your browser and shows it here. Nothing large is downloaded from our server.

Where 25 MB matters

A 26,214,400-byte file, 25 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 25 MB sample files

Use this file for

Testing image resizing and memory use
Checking that services convert BMP to a web format
Testing decoders for legacy formats

Testing notes for BMP

Row padding and bottom-up order are the usual causes of skewed or upside-down images in hand-written decoders.
Some validators accept BMP by MIME type but have no decoder for it, which fails later in the pipeline.

BMP format reference

Technical details

File name	sample-bmp-25mb.bmp
Format	BMP (Windows bitmap)
Extension	.bmp
MIME type	image/bmp
Size	26,214,400 bytes (25 MB)
Kind	Binary
Signature	42 4D
SHA-256	d28362e52271035522a534453c2dd46ee7f099d53a70d57c0bbe5f2fc9007073
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	Images

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-bmp-25mb.bmp     # Linux
shasum -a 256 sample-bmp-25mb.bmp # macOS

On Windows, run Get-FileHash sample-bmp-25mb.bmp -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 25 MB?: Yes. It is 26,214,400 bytes, which is 25 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 25 MB BMP file?: An uncompressed 3418 × 2556 test card. 10 bytes of unused space between the header and the pixel array bring the file to the exact size.
What bit depth are the BMP samples?: 24-bit RGB with no compression and no colour table.

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