Convert WebP to BMP
Output is typically roughly 17× larger.
- Files stay on your device
- Free, no sign-up
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Will converting WebP to BMP make the file smaller?
Usually, yes. A 12-megapixel photo is around 2.1 MB as WebP and around 36 MB as BMP — roughly 17× larger. Because BMP is lossless the result depends entirely on the image content — flat colour and text compress far better than photographic detail.
Does converting WebP to BMP lose quality?
No. BMP is lossless, so every pixel decoded from your WebP file is stored exactly. Both formats are lossless, so the conversion is pixel-for-pixel identical.
Is transparency preserved when converting WebP to BMP?
Yes. Both WebP and BMP support an alpha channel, so transparent and semi-transparent pixels carry across unchanged — a logo with a cut-out background stays cut out, and soft drop shadows keep their gradient rather than picking up a white halo. Because BMP is lossless, the alpha channel is stored exactly as it was.
What happens to an animated WebP?
Only the first frame is converted. Every conversion here decodes one frame onto a canvas and re-encodes it, so the result is always a still image — that applies to BMP as much as to any other target. To shrink an animation while keeping the motion, a video file (MP4 or WebM) is usually around a tenth of the size of the equivalent WebP, and needs an encoder we do not ship yet.
Why are BMP files so large?
BMP stores pixels essentially uncompressed — three or four bytes per pixel with no encoding at all. A 12-megapixel photo therefore lands around 36 MB, roughly 11× the same image as a JPEG. That simplicity is deliberate: legacy Windows software and embedded devices can read BMP with almost no code.
What kind of BMP does this produce?
An uncompressed 32-bit BMP with a BITMAPV4 header, which is the variant that carries an alpha channel reliably — plenty of BMP writers emit 24-bit files where transparency is silently dropped. Uncompressed means large: expect roughly four bytes per pixel, so a 12-megapixel photo lands around 48 MB regardless of what it started as.
How it works, and more about webp to bmp
How it works
- Add your WebP file. Drag a WebP file onto the drop zone, or click to browse. You can select several at once.
- Choose your settings. BMP is lossless, so there is nothing to configure — the output matches the input pixel for pixel.
- Download the BMP. Conversion runs on your device as soon as each file is added — no upload, no queue. Download each result when it is ready.
WebP and BMP side by side
| WebP | BMP | |
|---|---|---|
| Full name | WebP | Bitmap Image File |
| Compression | Lossy or lossless | Lossless |
| Transparency | Yes — alpha channel | Yes — alpha channel |
| Animation | Yes | No |
| Browser support | All modern browsers — Chrome 32+, Firefox 65+, Safari 14+ (2020), Edge 18+ | Supported in all major browsers, though rarely used on the web |
| Typical 12 MP photo | ~2.1 MB | ~36 MB |
| Usually used for | Web images where page weight matters and modern browsers are the audience | Legacy Windows applications, scanners and embedded displays |
On a typical 12-megapixel phone photo, the BMP output comes out roughly 17× larger than the WebP original. These are order-of-magnitude figures for one kind of image — your own results will vary a great deal, because flat colour, text and line art behave nothing like photographic detail.
What this tool actually produces
Not estimates. Each row below was produced by running the file through this page in a real browser and measuring the result, at the default quality of 82.
| Test image | WebP in | BMP out | Change |
|---|---|---|---|
| Smooth gradient 1600 × 1200, broad tonal transitions — where banding and blocking show | 175 KB | 7.3 MB | +4191% |
| UI screenshot 1440 × 900, dense text on flat panels — the hardest case for JPEG | 44 KB | 4.9 MB | +11418% |
| Line-art diagram 1200 × 800, hard edges and large flat areas | 12 KB | 3.7 MB | +29953% |
| Logo with transparency 512 × 512, flat colour on a transparent background | 7 KB | 1.0 MB | +14771% |
Every test image got larger. That is expected for this pair rather than a fault: BMP is not the efficient choice for content that already suits WebP, and you are converting for compatibility or for editing headroom, not to save space. Measured in Chrome 150.0.7871.46; other browsers encode slightly differently.
What to watch out for
- Massive files — often 10× a JPEG of the same image
- No animation, and inconsistent transparency support across variants
- Impractical for the web or for sharing
- Animation is lost. Only the first frame is converted — every conversion here decodes a single frame onto a canvas and re-encodes it, so the result is a still image whatever the target format. To shrink an animation and keep the motion, a video file is typically around a tenth of the size of the equivalent WebP.
About the two formats
WebP is the pragmatic modern choice for the web: roughly 25–35% smaller than JPEG at comparable quality, with transparency and animation that JPEG lacks, and — since Safari 14 in 2020 — support in every browser that matters. It is the format to reach for when you want smaller pages without worrying about fallbacks.
BMP stores pixels essentially uncompressed, which makes it enormous — a 12-megapixel photo lands around 36 MB, roughly 11× the same image as a JPEG. It persists mainly inside legacy Windows software, scanning utilities and embedded systems where decoding simplicity beats file size.
Other conversions
Everything runs on your device — nothing is uploaded, so there is no size limit, no queue and no copy left on a server afterwards. There is more on how browser-based conversion works if you want the detail. Otherwise, browse every image tool, or convert BMP back to WebP.