SampleTestFiles

25 KB BMP sample

A BMP file of exactly 25,600 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 KB sample, test or dummy BMP file.

Download

sample-bmp-25kb.bmp

25 KB25,600 bytes

Download 25 KB BMP

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
image/bmp
SHA-256
eb13e800d1caf199c692b32f7c3959fe8d1a8b645f014e5bf43932ce364e5c98
Delivery
Created in your browser from static generator assets (how it works).

What is in this file

An uncompressed 106 × 79 test card. 266 bytes of unused space between the header and the pixel array bring the file to the exact size.

Dimensions106 × 79 px
Bit depth24-bit RGB
CompressionNone (BI_RGB)
HeaderBITMAPINFOHEADER (40 bytes)
Row orderBottom-up

First bytes of the file

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

00000000  42 4d 00 64 00 00 00 00  00 00 40 01 00 00 28 00 |BM.d......@...(.|
00000010  00 00 6a 00 00 00 4f 00  00 00 01 00 18 00 00 00 |..j...O.........|
00000020  00 00 c0 62 00 00 13 0b  00 00 13 0b 00 00 00 00 |...b............|
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.

Where 25 KB matters

A 25,600-byte file: the size of a small web image or a short document. These are the default limits a file of this size is useful for testing:

SystemLimitNote
TCP initial congestion windowAbout 14.6 KB (10 segments)25 KB needs at least two flights of packets on a new connection.
Base64 encodingAdds 33 percentA 25 KB file becomes about 34 KB inside JSON or an email.

All 25 KB sample files

Use this file for

  • Checking thumbnail and icon handling
  • Testing decoders for legacy formats
  • Testing size limits with naturally large images

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 namesample-bmp-25kb.bmp
FormatBMP (Windows bitmap)
Extension.bmp
MIME typeimage/bmp
Size25,600 bytes (25 KB)
KindBinary
Signature42 4D
SHA-256eb13e800d1caf199c692b32f7c3959fe8d1a8b645f014e5bf43932ce364e5c98
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)
CategoryImages

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

On Windows, run Get-FileHash sample-bmp-25kb.bmp -Algorithm SHA256 in PowerShell. For scripts and pipelines, save the file once and keep your own copy.

Related files

Other BMP sizes

Other 25 KB files

Use cases

Guides

Questions about this file

Is this file exactly 25 KB?
Yes. It is 25,600 bytes, which is 25 KB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 25 KB BMP file?
An uncompressed 106 × 79 test card. 266 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.