BMP to PNG
Convert a BMP bitmap to a PNG with identical pixels and a smaller file, with nothing uploaded.
Your image is converted inside this page. It is never uploaded.
What this tool does
To convert BMP to PNG, choose the bitmap and download the PNG. PNG uses lossless compression, so every pixel is preserved exactly while the file is usually far smaller than the uncompressed BMP. It also supports transparency. The conversion runs in your browser.
Decodes your BMP in the browser and encodes the exact same pixels as a PNG.
Shows the original and new file sizes.
How to use it
- Choose a BMP file, or drop it into the box.
- The conversion runs automatically.
- Check the file sizes.
- Press Download.
- Open the PNG to confirm it matches the original.
Why use this converter
Converts BMP to PNG with no loss of quality, so the pixels are identical but the file is usually much smaller. A BMP and a PNG of the same picture look identical, but the PNG is lossless and compressed, so it is smaller and works everywhere on the web. For screenshots, diagrams and icons it is the right replacement for BMP.
Why we built it
We built the BMP to PNG converter so the pixels are identical but the file is usually much smaller. Use BMP to JPG for photos and the image format converter for WebP.
Who this tool is for
- People converting bitmaps without losing quality
- Designers working with legacy files
- Developers preparing assets
When to use it
- Old screenshots or graphics are in BMP format.
- A site or program will not accept BMP.
- You want a smaller file without any loss of quality.
- You need an image that supports transparency.
How it works
PNG compresses by predicting each pixel from its neighbours and encoding the small differences, then applying DEFLATE. It is fully reversible, so decoding the PNG gives back exactly the same pixels as the BMP.
Photographs compress less well in PNG than in JPG, so a BMP of a photograph may become a PNG that is smaller but still fairly large.
For photographs where small size matters more than perfect fidelity, BMP to JPG will give a much smaller file.
Tips for the best result
BMP files are uncompressed and large, so the main gain from converting is size. PNG stores the same pixels without loss, so nothing about the picture changes.
- Expect a much smaller file for flat graphics and screenshots, and a smaller gain for photographs.
- Check the size shown after conversion before you delete the original.
- Keep PNG for graphics and screenshots; use JPG if the image is a photograph and size matters more than exactness.
- Very large bitmaps use a lot of memory in the browser - close other tabs if conversion is slow.
What you give it, and what you get back
| Item | Details |
|---|---|
| Input | A BMP image. |
| Output | A PNG with identical pixels. |
| Report | Original and converted size. |
| Where it goes | Your Downloads folder. Nothing is uploaded. |
Issues you may run into
| What you see | Why it happens | What to do |
|---|---|---|
| PNG is still large | It is a photograph, which PNG compresses poorly. | Use BMP to JPG for photos. |
| File will not load | Some BMP variants are not supported by the browser. | Try re-saving it in another program. |
| Colours differ slightly | The BMP used an unusual colour mode. | Open it in an editor and re-export. |
| Transparency missing | BMP rarely carries an alpha channel. | There was none to preserve. |
Assumptions and limitations
- Photographs remain large in PNG.
- Some unusual BMP variants may not open.
- One file at a time.
- Metadata is not carried over.
Frequently asked questions
How do I convert BMP to PNG?
Choose the BMP and download the PNG. The conversion happens in your browser.
Is there any quality loss?
No. PNG is lossless, so the pixels are identical to the BMP.
Why is the PNG smaller than the BMP?
BMP is normally uncompressed, while PNG applies lossless compression to the same pixel data.
Should I use PNG or JPG?
PNG for screenshots, graphics and anything that must stay exact. JPG for photographs when file size matters more.
Is my image uploaded?
No. It is converted in your browser and saved to your Downloads folder.