How to Convert BMP to PNG
BMP is a format from a different era of computing. It stores every single pixel as raw bytes with no compression whatsoever, which made sense when processors were slow and disks were the cheaper resource — but today it means a single full-HD screenshot lands on your disk at nearly six megabytes when the identical image as PNG would be around six hundred kilobytes. Converting is the obvious fix, and because both formats are lossless, you give up nothing: the PNG contains exactly the same pixels, just stored intelligently instead of one after another. Drop your BMP files onto the panel above, or paste one from the clipboard, and each is decoded and re-encoded immediately in your browser — no upload, no queue, no server holding a copy of your images. The readout shows the saving per file and across the batch, which for screenshots and flat graphics regularly exceeds ninety per cent. Convert as many as you like at once and take the whole set as a single ZIP, and if the originals are bigger than you need, set a maximum width to scale them down during the same pass.
Add your BMP files
Drag and drop, paste, or click to browse — as many as you like.
Watch the saving
Each file shows its before-and-after size and reduction.
Download
Save each PNG, or grab the whole batch as one ZIP.
BMP vs PNG — What's the Difference?
BMP — Windows Bitmap
Introduced with early Windows, BMP writes pixel data straight to disk with essentially no compression. That makes it trivially simple for software to read and write, which is why old tools and some scanners still produce it — but the files are enormous and no browser will display one on a web page.
PNG — Portable Network Graphics
Designed for the web, PNG applies lossless compression, so nothing is thrown away yet files shrink dramatically. It also supports transparency and is understood by every browser, operating system and image editor in current use.
Common Use Cases
Shrink old screenshots
Windows-era screen captures saved as BMP drop by roughly 90%.
Publish on the web
Browsers won't render BMP in a page; PNG works everywhere.
Free up disk space
Convert an archive of BMP files and reclaim most of the storage.
Email attachments
A BMP can blow past attachment limits that PNG comfortably fits under.
Scanner output
Some scanners still default to BMP — convert the whole batch at once.
Legacy software exports
Older CAD, medical and industrial tools often only write BMP.
Game and app assets
Convert bitmap sprites to PNG for modern engines and toolchains.
Archive cleanup
Drop in a folder of BMP files and download the PNG set as one ZIP.
Tips & Best Practices
Nothing is lost, so convert freely
Both formats are lossless — the PNG holds exactly the same pixels, so there is no downside to converting.
Screenshots compress best
Flat colours and sharp edges suit PNG's compression, often shrinking by 95% or more.
Photographs save less
Photographic noise is harder to compress losslessly. If size matters more than fidelity, JPEG will be smaller still.
Batch a whole folder
Select every BMP at once and take the ZIP — far quicker than converting individually.
Resize if you only need it small
Scaling down cuts the file size far more than compression alone ever will.
Check 32-bit files for alpha
BMP files with an alpha channel keep their transparency in the PNG.
Troubleshooting
My BMP wouldn't open
Some rare BMP variants — certain RLE-compressed or exotic bit depths — aren't supported by browser decoders. Re-save it from an image editor first.
The saving was smaller than expected
Photographic content compresses less losslessly than flat graphics. Screenshots and diagrams see the biggest reductions.
Transparency disappeared
Only 32-bit BMP files carry an alpha channel. A 24-bit BMP has no transparency to preserve.
A very large file was slow
Uncompressed BMPs can be hundreds of megabytes. Conversion runs on your device, so speed depends on your machine's memory.
Frequently Asked Questions
How do I convert BMP to PNG for free?
Drop your BMP files onto the panel above and each is converted instantly. Download them individually or as a ZIP — free, no signup.
Will I lose any quality?
No. Both BMP and PNG are lossless, so the PNG is pixel-identical to the original.
How much smaller will the file be?
Typically 80 to 95% smaller. Screenshots and flat graphics often shrink by more than 95%.
Why is BMP so large?
It stores every pixel as raw bytes with no compression, so size depends only on dimensions and colour depth.
Are my images uploaded?
No. Conversion happens entirely in your browser, so images never leave your device.
Can I convert several files at once?
Yes. Add as many BMP files as you like and download the whole set as one ZIP.
Is there a file size limit?
No. Because nothing is uploaded, the only constraint is your device's available memory.
Is transparency preserved?
Yes, for 32-bit BMP files that have an alpha channel. A 24-bit BMP has no transparency to keep.
Can I resize while converting?
Yes. Set a maximum width and wider images are scaled down with high-quality smoothing.
Why won't browsers show BMP files?
Support is inconsistent and the files are impractically large for the web, so PNG or JPEG is always used instead.
Should I convert to JPG instead?
Choose JPEG only if you want a smaller photographic file and can accept lossy compression. PNG keeps every pixel exactly.
Does it remove metadata?
Yes. Canvas-based conversion drops any embedded metadata from the original file.
What about .dib files?
Device Independent Bitmap files use the same format and are accepted alongside .bmp.
How many files can I convert?
There's no cap — no daily quota and no queue, since everything runs locally.
Can I convert PNG back to BMP?
This tool converts one direction. Converting back would simply inflate the file with no benefit.
Does it work offline?
Once the page has loaded it runs entirely in your browser, so it keeps working without a connection.
Does it work on phones?
Yes, in any modern browser on Windows, Mac, Android or iPhone with nothing to install.
Is this converter really free?
Completely free, forever — no account, no ads and no premium wall.
100% free · No signup · Converted in your browser · Never uploaded
Last updated: August 2026 · FlipMyFormat BMP to PNG Converter
Written and maintained by the FlipMyFormat team · Runs entirely in your browser