Convert BMP to PNG Online — Free & Private
Converting BMP to PNG re-encodes an image from Bitmap Image File / Device Independent Bitmap into Portable Network Graphics. This free converter does it entirely inside your browser — your files are never uploaded — and handles unlimited batches with no sign-up, no watermark and no software to install.
Drag & drop your BMP files here
Batch conversion supported · up to 50 MB per file
🔒 Processed locally in your browser — nothing is uploaded.
How to convert BMP to PNG
To convert BMP to PNG: add your files to the converter above, confirm PNG is selected as the output format, press Convert, then download the result. The whole process runs in your browser and takes a few seconds.
- Add your files. Drag BMP files onto the box above, or click Choose files to browse. Multiple files at once are fine — there is no limit on how many.
- Check the settings. PNG is already selected. Quality is fixed because this target is lossless. Turn on Resize output if you need specific dimensions.
- Press Convert. Each file is decoded, redrawn and re-encoded on your device, with progress shown per file.
- Download. Take files individually, or use Download all as ZIP for the whole batch.
Why convert BMP to PNG?
Converting BMP to PNG usually comes down to compatibility or file size. Logos, screenshots, diagrams, icons and any graphic with sharp edges, flat colour or transparency.
BMP vs PNG: what actually changes?
The practical differences are compression, transparency and compatibility. BMP is uncompressed with only in the rarely supported 32-bit variant transparency; PNG is lossless with full 8-bit alpha channel — 256 levels of transparency transparency. The table below sets out every difference that affects the result.
| Property | BMP | PNG |
|---|---|---|
| Compression | Uncompressed | Lossless |
| Transparency | Only in the rarely supported 32-bit variant | Full 8-bit alpha channel — 256 levels of transparency |
| Animation | Not supported | Only via the separate APNG extension |
| Colour depth | 1, 4, 8, 16, 24 or 32-bit | Up to 48-bit colour, plus a 16-bit alpha channel |
| Introduced | 1990 | 1996 |
| Browser support | Supported for display, but effectively never used on the web | Universal — supported everywhere since the late 1990s |
| Typical size | Frequently 20–50× a JPG of the same image | Roughly 5–10× a JPG for photographs; often smaller for flat graphics |
| Best for | Legacy Windows software and embedded systems that need raw pixel data with no decoding step. | Logos, screenshots, diagrams, icons and any graphic with sharp edges, flat colour or transparency. |
What is a BMP file?
BMP stands for Bitmap Image File / Device Independent Bitmap. Introduced in 1990 by Microsoft, it uses uncompressed compression and is best suited to legacy Windows software and embedded systems that need raw pixel data with no decoding step.
An uncompressed Windows bitmap. Enormous files, but dead simple — still used by some legacy Windows and embedded software.
| Property | BMP |
|---|---|
| Full name | Bitmap Image File / Device Independent Bitmap |
| File extensions | .bmp, .dib |
| MIME type | image/bmp |
| Introduced | 1990 |
| Developed by | Microsoft |
| Compression | Uncompressed |
| Colour depth | 1, 4, 8, 16, 24 or 32-bit |
| Transparency | Only in the rarely supported 32-bit variant |
| Animation | Not supported |
| Browser support | Supported for display, but effectively never used on the web |
| Typical file size | Frequently 20–50× a JPG of the same image |
BMP strengths
- Dead simple structure — trivial for any program to read
- No compression means no compression artefacts at all
- Long-standing support across Windows tooling
BMP limitations
- Enormous files — width × height × 3 bytes, with no compression
- Transparency support is inconsistent in practice
- Nobody uses it on the web, for good reason
What is a PNG file?
PNG stands for Portable Network Graphics. Introduced in 1996 by PNG Development Group, later a W3C Recommendation, it uses lossless compression and is best suited to logos, screenshots, diagrams, icons and any graphic with sharp edges, flat colour or transparency.
Lossless compression with full alpha transparency. The right choice for logos, screenshots, diagrams and any graphic with sharp edges or flat colour.
| Property | PNG |
|---|---|
| Full name | Portable Network Graphics |
| File extensions | .png |
| MIME type | image/png |
| Introduced | 1996 |
| Developed by | PNG Development Group, later a W3C Recommendation |
| Compression | Lossless |
| Colour depth | Up to 48-bit colour, plus a 16-bit alpha channel |
| Transparency | Full 8-bit alpha channel — 256 levels of transparency |
| Animation | Only via the separate APNG extension |
| Browser support | Universal — supported everywhere since the late 1990s |
| Typical file size | Roughly 5–10× a JPG for photographs; often smaller for flat graphics |
PNG strengths
- Lossless — the decoded pixels are exactly the ones you saved
- True alpha transparency with soft edges
- Re-saving never degrades the image
PNG limitations
- Files are much larger than JPG for photographs
- No native animation support
- No CMYK, so it is unsuitable for professional print work
Does converting BMP to PNG lose quality?
No. PNG is lossless, so the conversion writes every decoded pixel exactly as it is. Note that any quality already lost inside the original BMP file cannot be recovered — lossless means nothing further is lost, not that damage is undone.
Two distinct things are often confused here. The first is whether the target format discards data: PNG is lossless, so it does not. The second is whether the source already lost data: BMP is uncompressed, so the source holds the original detail intact.
A practical rule: converting repeatedly between lossy formats compounds the damage each time. If you expect to edit an image more than once, work in a lossless format and export to a lossy one only at the end.
Is it safe to convert BMP files here?
Yes, and you can verify it rather than trust it. Your BMP file is read, decoded and re-encoded inside your browser tab. There is no upload endpoint on our side, so no copy of your image exists anywhere but your own device.
Most online converters upload your file to a server, process it there and promise to delete it later. That promise is unverifiable, and it does not survive a breach, a misconfigured storage bucket or a legal request. This tool removes the question entirely: the code comes to you, the file stays put.
To confirm it for yourself, open your browser’s developer tools, switch to the Network tab, and convert a file. You will see the page assets load and nothing carrying your image leave. It also works with your connection switched off entirely, once the page has loaded.
BMP and PNG at a glance
BMP files use the image/bmp MIME type and the .bmp extension; PNG files use image/png and .png. The summary below covers the properties that matter when choosing between them.
| BMP | PNG | |
|---|---|---|
| Full name | Bitmap Image File / Device Independent Bitmap | Portable Network Graphics |
| Extension | .bmp, .dib | .png |
| MIME type | image/bmp | image/png |
| Year | 1990 | 1996 |
| Best for | Legacy Windows software and embedded systems that need raw pixel data with no decoding step. | Logos, screenshots, diagrams, icons and any graphic with sharp edges, flat colour or transparency. |
BMP to PNG: frequently asked questions
- How do I convert BMP to PNG?
- Open this page, drag your BMP files onto the drop zone, and press Convert. PNG is already selected as the output format. The conversion runs in your browser and finishes in seconds, then you download the result individually or as a ZIP.
- Is this BMP to PNG converter free?
- Yes, completely. There is no account, no daily limit, no watermark and no paid tier. You can convert as many BMP files as you like, as often as you like.
- Are my BMP files uploaded to a server?
- No. The conversion runs entirely in your browser using the Canvas API and WebAssembly codecs. Nothing about your file is transmitted to us, so there is nothing for us to store, share or lose. You can verify this by opening your browser's Network tab while converting.
- Will converting BMP to PNG reduce quality?
- PNG is lossless, so every pixel that survives decoding is written exactly as it is. No further quality is lost in the conversion itself.
- Will the file get bigger or smaller?
- PNG files are typically roughly 5–10× a jpg for photographs; often smaller for flat graphics, against frequently 20–50× a jpg of the same image for BMP. The converter shows the before and after size for every file so you can see the exact result.
- Can I convert multiple BMP files at once?
- Yes. Drop the whole batch in and they convert one after another with individual progress. Download them one by one, or take the entire set as a single ZIP file built in your browser.
- Does PNG support transparency?
- Yes — full 8-bit alpha channel — 256 levels of transparency. Transparent areas in your BMP file are preserved in the PNG output.
- Is there a file size limit?
- Each file is capped at 50 MB, because conversion happens in your browser's memory and very large files can crash a tab, particularly on phones. There is no limit on how many files you convert.
- Does it work on iPhone, Android, Mac and Windows?
- Yes. It runs in any modern browser on any operating system — there is nothing to install. Universal — supported everywhere since the late 1990s.
- Do I need to install software or sign up?
- Neither. There is no download, no extension, no account and no email address required. Open the page and convert.
Related conversions
Need to go the other way? Try PNG to BMP. Other conversions involving these formats: