500 KB BMP sample

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

sample-bmp-500kb.bmp

500 KB512,000 bytes

Download 500 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: 177e9f3555e66c7570d69f267c0c03b465dc85e129dece330ab35f68fe833cf3
Delivery: Created in your browser from static generator assets (how it works).

What is in this file

An uncompressed 477 × 357 test card. 722 bytes of unused space between the header and the pixel array bring the file to the exact size.

Dimensions	477 × 357 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-500kb.bmp as a hex dump: offset, bytes, then the same bytes as text. The BMP signature is 42 4D.

00000000  42 4d 00 d0 07 00 00 00  00 00 08 03 00 00 28 00 |BM............(.|
00000010  00 00 dd 01 00 00 65 01  00 00 01 00 18 00 00 00 |......e.........|
00000020  00 00 f8 cc 07 00 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.

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 decoders for legacy formats
Testing size limits with naturally large images

Testing notes for BMP

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

BMP format reference

Technical details

File name	sample-bmp-500kb.bmp
Format	BMP (Windows bitmap)
Extension	.bmp
MIME type	image/bmp
Size	512,000 bytes (500 KB)
Kind	Binary
Signature	42 4D
SHA-256	177e9f3555e66c7570d69f267c0c03b465dc85e129dece330ab35f68fe833cf3
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-500kb.bmp     # Linux
shasum -a 256 sample-bmp-500kb.bmp # macOS

On Windows, run Get-FileHash sample-bmp-500kb.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 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 BMP file?: An uncompressed 477 × 357 test card. 722 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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