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What is a BMP file?

BMP stores a picture as plain rows of pixels with nothing squeezed out, which makes it easy for old Windows software and simple devices to read. The cost is size: a BMP is routinely many times larger than the same picture as a PNG. You can convert BMP files here, both into the format and out of it.

Specification

BMP format specifications
Full nameBitmap Image File
Extensions.bmp, .dib
Media typeimage/bmp
CompressionUncompressed
TransparencySupported
AnimationNot supported
Multiple pages
Colour depth1, 4, 8, 16, 24 or 32 bits per pixel
Size limits
Introduced1986
Developed byMicrosoft
StandardProprietary
Browser supportAll current browsers

What BMP is used for

  • Windows application resources and legacy tooling
  • Embedded devices and firmware that cannot afford a decoder
  • Intermediate files in scientific or industrial pipelines
  • Testing and debugging, where getting straight at the picture is convenient

Strengths and limitations

What BMP does well

  • Nothing is squeezed, so there is nothing to go wrong and nothing to unpack
  • Simple enough that almost any program can read it
  • Reliably supported across the Windows ecosystem

Where BMP falls short

  • Files are enormous, often ten to fifty times a comparable PNG
  • Essentially unusable on the web because of that size
  • Barely any support for colour management or file details

Convert BMP to

Every target this format can be written out as, each on its own page.

Convert to BMP

Everything that can be turned into a BMP file.

Tools that accept BMP

Questions about BMP

What is a .bmp file?

BMP stores a picture as plain rows of pixels with nothing squeezed out, which makes it easy for old Windows software and simple devices to read. The extension .bmp or .dib identifies it, and its media type is image/bmp.

How do I open a BMP file?

Any current browser will open it directly, so dragging the file into a tab is usually enough. Most operating systems also preview it without extra software.

Is BMP lossy or lossless?

Uncompressed. Nothing is discarded, so repeated saves never degrade the contents.

What is BMP good for?

Nothing is squeezed, so there is nothing to go wrong and nothing to unpack. Simple enough that almost any program can read it. Reliably supported across the Windows ecosystem. In practice that makes it a good fit for windows application resources and legacy tooling, and Embedded devices and firmware that cannot afford a decoder.

What are the drawbacks of BMP?

Files are enormous, often ten to fifty times a comparable PNG. Essentially unusable on the web because of that size. Barely any support for colour management or file details.

Other image formats

Images converter or the full format reference