BMP3 File Format (.bmp3)

BMP3 is ImageMagick's name for a Windows bitmap saved with the 40-byte BITMAPINFOHEADER that Windows 3.0 introduced in 1990, an encoding choice rather than a different file format, and it's the header structure the overwhelming majority of ordinary .bmp files already use.

.bmp3Image Files

BMP3 at a glance#

Full name	Microsoft Windows bitmap image (V3)
File extension	.bmp3
Category	Image Files
MIME types	image/bmp
Other extensions	.bmp
Compression	Uncompressed
FileFlip support	FileFlip reads and writes this format

What a .bmp3 file can hold#

These are the things a BMP3 file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.

Transparency (alpha channel)	No
Lossless compression	Yes
Embedded metadata	No
Colour profiles	No

Strengths and limitations of BMP3#

What BMP3 does well

Supports 1, 4, 8, 16, 24 and 32-bit pixel formats, unlike the older 12-byte header
Supports RLE4 and RLE8 run-length compression for palette images
Readable by essentially every image viewer and editor written for Windows since 1990

Where BMP3 falls short

No native alpha channel; that arrived later with the BITMAPV4HEADER and BITMAPV5HEADER structures
RLE compression applies only to 4-bit and 8-bit palette images, not to 24-bit or 32-bit ones

Choose BMP3 for maximum compatibility, since it's the header format nearly all BMP-reading software expects.

Convert away from BMP to PNG when the image needs transparency, or when you want lossless compression smaller than BMP3's largely uncompressed pixel data.

How to open a .bmp3 file#

A .bmp3 file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts BMP3 into a format your machine already opens, and it does it in the browser tab rather than on a server.

Platform	Programs that open it
Windows	Paint, Photos, IrfanView, Adobe Photoshop
macOS	Preview, GIMP, Adobe Photoshop
Linux	GIMP, ImageMagick
Web	FileFlip

BMP3 questions people ask#

What is BMP3?

BMP3 is ImageMagick's name for a standard Windows bitmap written with the 40-byte BITMAPINFOHEADER, not a separate format. It's the same header structure that almost every ordinary .bmp file already uses.

Is BMP3 the same as a normal BMP file?

Yes, in practice. Windows has used the BITMAPINFOHEADER as its default bitmap header since Windows 3.0 in 1990, so a plain .bmp saved by most modern software is already what ImageMagick calls BMP3.

Does BMP3 support transparency?

No. The BITMAPINFOHEADER that BMP3 writes has no alpha channel; that was added in later Windows header versions. A BMP3 file is always fully opaque.

Converting BMP3 files#

Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.