Image
Windows Bitmap is a image format commonly identified by .bmp, .dib. Use the listed signatures, MIME types, and structure notes to validate files beyond the extension.
42 4D BMSIGNATURE = bytes.fromhex("424d")
OFFSET = 0
def is_bmp(path: str) -> bool:
with open(path, "rb") as f:
f.seek(OFFSET)
head = f.read(len(SIGNATURE))
return head == SIGNATUREconst SIGNATURE = [0x42, 0x4d];
const OFFSET = 0;
// bytes: a Uint8Array / Buffer holding the start of the file
export function isBmp(bytes) {
return SIGNATURE.every((byte, i) => bytes[OFFSET + i] === byte);
}package fileid
import "bytes"
var isbmpSignature = []byte{0x42, 0x4d}
const isbmpOffset = 0
func IsBmp(b []byte) bool {
end := isbmpOffset + len(isbmpSignature)
if len(b) < end {
return false
}
return bytes.Equal(b[isbmpOffset:end], isbmpSignature)
}const SIGNATURE: &[u8] = &[0x42, 0x4d];
const OFFSET: usize = 0;
fn is_bmp(bytes: &[u8]) -> bool {
bytes.get(OFFSET..OFFSET + SIGNATURE.len()) == Some(SIGNATURE)
}<?php
$signature = "\x42\x4d";
$offset = 0;
function is_bmp(string $bytes): bool {
global $signature, $offset;
return substr($bytes, $offset, strlen($signature)) === $signature;
}Windows Bitmap is commonly used for image previews, thumbnails, metadata checks, and upload validation. Test multiple sizes because resolution, alpha support, compression, and file size often affect implementation behavior.
Media files can still stress decoders through corrupt metadata, extreme dimensions, long durations, or unusual chunks. Read size, dimensions, and duration before processing.
11 samples help test tiny images, high-resolution images, alpha channels, and hard-to-compress assets.
Flower Garden BMP is a Windows Bitmap sample based on Wikimedia Commons, 960 x 540. It can be used to test downloads, parsers, previews, and file type detection.
flower-garden.bmp20168aa7ce4606e585704083cd724df1125fa00393a9544253a67b420c501c11
Blue Sky BMP is a Windows Bitmap sample based on Wikimedia Commons, 96 x 72. It can be used to test downloads, parsers, previews, and file type detection.
01-blue-sky.bmp4eb92e5e90fe8f5db763d86c90e5edbbedb528f74da8e86d7df3d9f86e8a97b4
Flower Garden BMP is a Windows Bitmap sample based on Wikimedia Commons, 160 x 90. It can be used to test downloads, parsers, previews, and file type detection.
02-flower-garden.bmpab2ba06de24e5e14216b7776893ed83553effd903885322b3001e352848f1f91
Navy Blue Sky BMP is a Windows Bitmap sample based on Wikimedia Commons, 256 x 128. It can be used to test downloads, parsers, previews, and file type detection.
03-navy-blue-sky.bmpbf2979e754d0dc037ca38069660421dcbe0242d259a561536b6d9ae1faf1f1e2
Nature of the Sky BMP is a Windows Bitmap sample based on Wikimedia Commons, 360 x 270. It can be used to test downloads, parsers, previews, and file type detection.
04-nature-sky.bmpee8aec450b9063e52f737c7c925e0110ec83b608b1d4cb5eda95452a33667f3a
Sky Landscape BMP is a Windows Bitmap sample based on Wikimedia Commons, 512 x 384. It can be used to test downloads, parsers, previews, and file type detection.
05-sky-landscape.bmpb31a1aa2677aa0e8d9d03f898f02345a3c09f5fa052d6130c5e3e40c1bb8d7e1
Starry Sky BMP is a Windows Bitmap sample based on Wikimedia Commons, 720 x 480. It can be used to test downloads, parsers, previews, and file type detection.
06-starry-sky.bmp9a906ff6465e7e95dac75ec3e668c7bb3a5ef49d7e47fa78e71e118f8ac80e9a
Blue Night Sky BMP is a Windows Bitmap sample based on Wikimedia Commons, 960 x 640. It can be used to test downloads, parsers, previews, and file type detection.
07-blue-night-sky.bmp24e10e169c35cae48959735dd2e22c4efeda4af70920610dc5338e878da71d88
Hibiscus Flower BMP is a Windows Bitmap sample based on Wikimedia Commons, 1280 x 2770. It can be used to test downloads, parsers, previews, and file type detection.
08-hibiscus-flower.bmpf5ab30cd048fb4d6bd169d3becf00c821285119117d07120bc54ce29ec2fded2
Arctic Sky BMP is a Windows Bitmap sample based on Wikimedia Commons, 1600 x 1062. It can be used to test downloads, parsers, previews, and file type detection.
09-arctic-sky.bmp6beb2e836570ddae27e5cc19ae84dd5da2dd0f9b997bbf473ebb810e0313e256
NASA Blue Marble BMP is a Windows Bitmap sample based on NASA Image and Video Library, 640 x 640. It can be used to test downloads, parsers, previews, and file type detection.
nasa-blue-marble-2012-east.bmp4ef15ea61207fb39f3e456260d2571036f2214a352c24bde8badae69cef49e74Windows Bitmap files begin with the byte signature 42 4D ("BM"). Detect the format by reading these leading bytes rather than trusting the file extension alone.
The MIME type for Windows Bitmap is image/bmp, image/x-ms-bmp.
Windows Bitmap files use the .bmp, .dib extension. The extension is a convention only and does not guarantee the file contents, so combine it with signature and structure checks.
