Convert PNG to BMP: Free Online, CLI, and Desktop Methods

Most image conversions go the other direction — BMP to something modern. But sometimes you need the old format. Legacy software, embedded systems, and certain hardware still demand BMP files. Here is how to convert PNG to BMP quickly and for free.

Why Convert PNG to BMP?

PNG is the better format in almost every way. So why go backward?

• Legacy software compatibility. Older Windows applications, industrial control systems, and scientific instruments that only accept BMP input.
• Embedded systems and hardware. Microcontrollers, LCD displays, and POS terminals that expect raw bitmap data for direct framebuffer rendering.
• Windows application icons. The ICO format is BMP-based internally. Some icon editors require BMP source files.
• CNC machines and laser cutters. Fabrication equipment that reads raw pixel grids for engraving patterns.

If none of these apply, you almost certainly do not need BMP. Stick with PNG or consider WebP for even smaller files. For a full explanation of the format, see What is BMP?.

PNG vs BMP: What Changes

The big hits: file size balloons (typically 2-4x larger) and transparency disappears. Most BMP implementations ignore the alpha channel, so transparent areas fill with a solid color — usually white. Pixel data itself is preserved with zero quality loss.

Need the reverse? See how to convert BMP to PNG. Or try BMP to JPG for lossy compression.

Method 1: Pixotter Online Converter

The fastest option. Pixotter's converter runs entirely in your browser using WebAssembly. Your image never leaves your device — no upload, no server, no waiting.

1. Open pixotter.com/convert/
2. Drop your PNG file onto the drop zone (or click to browse)
3. Select BMP as the output format
4. Click Convert — download starts immediately

No account, no installation. Works on Chrome, Firefox, Safari, and Edge. For multiple files, drop them all at once — Pixotter packages the results as a ZIP download.

Method 2: ImageMagick 7.1.1-41 (CLI)

ImageMagick (Apache-2.0 license) is the standard command-line tool for image conversion. Install via sudo apt install imagemagick on Ubuntu/Debian, brew install imagemagick on macOS, or download from imagemagick.org on Windows.

Convert a single file:

magick input.png output.bmp

Convert with maximum legacy compatibility (BMP version 3, no alpha):

magick input.png -alpha remove -alpha off -depth 8 BMP3:output.bmp

The BMP3 prefix forces BMP version 3, the most widely compatible variant. The -alpha remove flag composites transparency onto white by default — use -background "#FF0000" before it to pick a different color.

Batch convert every PNG in a folder:

magick mogrify -format bmp *.png

Creates a .bmp file alongside each .png. Originals are untouched.

Method 3: GIMP 2.10.38

GIMP (GPL-3.0 license) is a free image editor for Linux, macOS, and Windows.

1. Open your PNG file in GIMP 2.10.38 (File > Open)
2. If the image has transparency, flatten first: Image > Flatten Image (composites onto white)
3. Go to File > Export As
4. Change the file extension to .bmp
5. Click Export, leave defaults (24-bit, no RLE compression), and click Export again

GIMP gives you the most control — you can choose the background color before flattening and adjust color depth for specific hardware requirements.

Method 4: Windows Paint

Already installed on every Windows machine. No download needed.

1. Open your PNG file in Paint (right-click the file, select Open with > Paint)
2. Click File > Save as > BMP picture
3. In the Save as type dropdown, select the BMP variant you need:
   • 24-bit Bitmap — most compatible, no transparency
   • 256 Color Bitmap — 8-bit, smaller file, color reduction
   • Monochrome Bitmap — 1-bit, black and white only
4. Click Save

Paint automatically removes transparency and composites onto a white background. For most legacy software requirements, 24-bit Bitmap is the correct choice.

FAQ

Does converting PNG to BMP lose quality?

No. BMP is uncompressed, so every pixel from the original PNG is preserved exactly. The only change is file size (it grows) and transparency (it disappears in most BMP variants).

What happens to transparency when I convert PNG to BMP?

Most BMP implementations do not support alpha transparency. Transparent areas are filled with a solid background color — white by default in most tools. In ImageMagick 7.1.1-41, you can set a custom background color with the -background flag before removing alpha.

Why is my BMP file so much larger than the PNG?

PNG uses lossless DEFLATE compression. BMP stores every pixel uncompressed. A 1920x1080 image at 24-bit color takes roughly 6 MB as BMP versus 1.5-3 MB as PNG. The image data is identical — BMP just uses more disk space to store it.

Can I convert PNG to BMP without installing software?

Yes. Pixotter's converter runs in your browser and processes images entirely on your device. No download, no account, no server upload.

Is there a 32-bit BMP that supports transparency?

BMP version 4 and 5 include a 32-bit format with an alpha channel, but support is inconsistent. Many applications that require BMP input ignore the alpha channel entirely. If the receiving software specifically documents support for 32-bit BMP with alpha, it can work — but test before committing to it.

Can I batch convert multiple PNG files to BMP?

Yes. Drop multiple files onto Pixotter's converter at once. With ImageMagick 7.1.1-41, run magick mogrify -format bmp *.png to convert an entire folder.

What BMP version should I use for maximum compatibility?

BMP version 3 (also called BITMAPINFOHEADER) is the most widely supported. In ImageMagick, use the BMP3: prefix: magick input.png BMP3:output.bmp. This works with virtually all legacy software.

Is BMP better than PNG for anything?

Only for simplicity of parsing. BMP's uncompressed pixel grid can be read by extremely minimal software — microcontrollers, boot screens, and systems without a DEFLATE decompressor. For everything else, PNG is the better format.

Wrapping Up

Converting PNG to BMP is straightforward with any of these four methods. Pixotter is the fastest for browser-based conversion with no install. ImageMagick 7.1.1-41 handles batch jobs and gives you control over BMP version and alpha handling. GIMP 2.10.38 offers a full visual workflow. Paint works for quick one-off conversions on Windows.

Just remember: BMP files are uncompressed and significantly larger, and you lose PNG's transparency. Only convert when a specific application or device actually requires BMP — for everything else, keep your images in PNG.