What is a BMP file?
BMP stands for Bitmap image. It was created by Microsoft and first released in 1990. BMP usually stores pixels with no compression at all, so a 12 megapixel photo is about 36 MB. That size is the price of being readable by almost any program ever written for Windows.
DIB is the same format under another extension.
| Type | image |
|---|---|
| Compression | Lossless |
| Colour | up to 32-bit colour |
| Transparency | Yes |
| Animation | No |
| In a browser | opens in browsers and every Windows image tool |
| Common uses | Windows software, embedded displays and legacy tools |
| MIME type | image/bmp |
Which format should you convert BMP to?
- BMP to JPG for photos that must open everywhere and stay small.
- BMP to PNG for screenshots, logos and anything with transparency.
- BMP to WebP for the smallest file on a website.
- BMP to PDF to print, or to attach as a document.
- BMP to ICO to use as a website favicon.
BMP is lossless, so converting it to a lossy format is where the file gets much smaller.
How to open a BMP file
Whether a BMP file opens with a double click depends on the device. Here is what works on each, without buying software:
| Windows | The Photos app opens common image formats. If BMP is not among them, a browser or a free viewer such as IrfanView will open it. |
|---|---|
| Mac | Preview opens most image formats and PDF files; Quick Look (press the space bar in Finder) shows a preview without opening an app. |
| iPhone and iPad | The Files app and Photos show common image types and PDF files. Other formats need an app, or converting here. |
| Android | Google Photos and Files by Google open common images and PDFs. Other formats need a viewer app, or converting here. |
| Web browser | BMP opens in browsers and every Windows image tool. |
Want the technical details? See what a .bmp file is, with its MIME type, file signature and a viewer.
BMP compared with other image formats
How BMP stacks up against the formats people most often convert it to or from:
| Format | Compression | Transparency | Released | Best for |
|---|---|---|---|---|
| BMP | Lossless | Yes | 1990 | Windows software, embedded displays and legacy tools |
| JPG | Lossy | No | 1992 | camera photos, web images and email attachments |
| PNG | Lossless | Yes | 1996 | screenshots, logos, diagrams and anything with transparency |
| WebP | Either | Yes | 2010 | images served by websites to save bandwidth |
| HEIC | Lossy | Yes | 2017 | photos taken on iPhones and iPads since iOS 11 |
How to use the BMP converter
- Choose the format you want in the Convert to menu.
- Drop your BMP files on the box, or press Choose BMP files. Several files can go in at once.
- Adjust the settings if you need to; the defaults suit most people.
- Press Convert and save each file with its Download button. Converting to DDS, PCX, PSD uses our server, which deletes the file right after; the rest never leave your device.
Tips for converting BMP files without losing quality
BMP is lossless, so it is a good source for any conversion. Converting it to a lossy format is where the file gets much smaller, and converting it to another lossless format keeps every pixel.
- Choose by content: photos belong in JPG or WebP, while screenshots, logos and anything with transparency belong in PNG or WebP.
- Resize before you send. A modern phone photo is far wider than any screen, and scaling it to 1920 pixels removes most of the file size.
- Keep originals. Re-saving a JPG again and again slowly degrades it; convert from the original each time.
- Converting through the browser removes EXIF metadata such as GPS location, which is useful when sharing photos publicly.
Convert BMP files from the command line
Everything this page does can also be done in a terminal. The most common BMP conversion, to JPG, looks like this with ImageMagick:
magick input.bmp output.jpgChange the output extension to pick another format. The converter above runs the same kind of conversion inside your browser, so you get the result without installing anything.
BMP converter FAQ
What is a BMP file?
BMP stands for Bitmap image, an image format created by Microsoft in 1990. BMP usually stores pixels with no compression at all, so a 12 megapixel photo is about 36 MB. That size is the price of being readable by almost any program ever written for Windows.
How do I open a BMP file?
BMP opens in browsers and every Windows image tool. If the program you need will not open it, convert it to a more widely supported format above.
What is the most common BMP conversion?
BMP to JPG is the conversion people search for most. The image is decoded and written as a baseline JPEG at 90 percent quality.
Does converting BMP files here upload them?
Only for some conversions. Converting to DDS, PCX, PSD uses our conversion server, where the file is deleted as soon as the result is sent back; the other conversions run inside your browser and never leave your device.
Is the BMP converter free?
Yes. There is no sign-up and no watermark. Conversions that use our server accept files up to 25 MB, with a fair-use limit per hour. The site is supported by advertising.
Can I convert BMP files on iPhone or Android?
Yes. Open this page in Safari on iPhone and iPad, or in Chrome on Android, choose your BMP files and download the results to your Downloads folder.
Can I convert several BMP files at once?
Yes. Drop as many as you like; they are converted one after another, each with its own download button.