Convert JPG to BMP
Output is typically roughly 11× larger.
- Files stay on your device
- Free, no sign-up
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Will converting JPG to BMP make the file smaller?
Usually, yes. A 12-megapixel photo is around 3.2 MB as JPG and around 36 MB as BMP — roughly 11× 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 JPG to BMP lose quality?
No. BMP is lossless, so every pixel decoded from your JPG file is stored exactly. Note that any compression artefacts already baked into the JPG original are preserved too — converting to a lossless format cannot recover detail that was thrown away earlier.
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 jpg to bmp
How it works
- Add your JPG file. Drag a JPG 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.
JPG and BMP side by side
| JPG | BMP | |
|---|---|---|
| Full name | JPEG | Bitmap Image File |
| Compression | Lossy | Lossless |
| Transparency | No | Yes — alpha channel |
| Animation | No | No |
| Browser support | Universal — every browser, every device | Supported in all major browsers, though rarely used on the web |
| Typical 12 MP photo | ~3.2 MB | ~36 MB |
| Usually used for | Photographs, email attachments and anything needing maximum compatibility | Legacy Windows applications, scanners and embedded displays |
On a typical 12-megapixel phone photo, the BMP output comes out roughly 11× larger than the JPG 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 | JPG in | BMP out | Change |
|---|---|---|---|
| Smooth gradient 1600 × 1200, broad tonal transitions — where banding and blocking show | 236 KB | 7.3 MB | +3076% |
| UI screenshot 1440 × 900, dense text on flat panels — the hardest case for JPEG | 159 KB | 4.9 MB | +3077% |
| Line-art diagram 1200 × 800, hard edges and large flat areas | 83 KB | 3.7 MB | +4427% |
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 JPG, 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
About the two formats
JPEG has been the default photo format for three decades, and its compatibility is unmatched — if a device can display an image at all, it can display a JPEG. The trade-offs are that it discards detail permanently on every save, and it has no transparency channel at all, so anything transparent becomes a solid background.
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 JPG.