Convert BMP to JPG — shrink legacy bitmaps by 95 percent
Drop a BMP below and get a JPG that is typically 20 to 50 times smaller, with no visible quality loss. The conversion runs locally in your browser — no upload.
Your file is processed entirely in your browser. Nothing is uploaded.
The BMP format, short for Bitmap, was Microsoft’s original image format for Windows and has been around since 1986. It stores images as a raw grid of pixels with essentially no compression, which means BMP files are almost always enormous — a single 4K screenshot can weigh 32 MB in BMP while the same image in JPG at quality 85 weighs about 800 KB. If you have a folder full of old BMP files from legacy Windows software, Paint exports, screen-capture utilities, or scanner output, converting them to JPG is one of the fastest ways to reclaim tens of gigabytes of disk space.
This converter reads your BMP through the Canvas API, which supports BMP natively in all modern browsers, then re-encodes it as a JPG at your chosen quality level. The encoding is lossy, but at quality 85 or higher the difference is imperceptible on photographic content. The entire process runs in your browser — your BMPs never leave your device. If you want lossless output (same pixels, just smaller file), convert to PNG instead: PNG can typically shrink a BMP by 50 to 70 percent without any quality change.
How to convert BMP to JPG in 4 steps
- 1
Select your BMP
Drop the file in the dropzone or click to browse. BMPs of any color depth your browser supports are accepted: 1-bit, 8-bit, 24-bit, 32-bit.
- 2
Pick a quality level
The default of 85 is a good balance. Go higher for photographs you want to archive, lower if storage is more important than pixel-perfect fidelity.
- 3
Let Canvas re-encode
The browser decodes the raw BMP pixels and encodes them as JPG. Even huge BMPs (50+ MB) typically finish in a couple of seconds on a modern device.
- 4
Download the compact JPG
Save your JPG and delete the original BMP if you no longer need it. You will reclaim 95 percent or more of the original disk space.
BMP vs JPG: raw pixels versus smart compression
BMP stores each pixel as a raw color value — typically 24 or 32 bits per pixel — with optional minimal run-length encoding that barely helps. A 1920x1080 BMP at 24 bpp weighs 5.93 MB uncompressed; the same image in JPG at quality 85 weighs about 200 KB. That is a 30x size reduction for a difference no human eye can detect on a photograph. JPG achieves this using a frequency-domain compression scheme designed specifically for photographic content: it transforms blocks of pixels into frequency coefficients, discards the ones the human visual system is least sensitive to, and encodes the rest efficiently. For practical purposes, JPG is strictly better than BMP for everyday photographs. The only reason to keep BMP is if you are working in an extremely specific Windows workflow that expects the format.
When should you convert BMP to JPG?
Reclaiming disk space from old BMP archives
Many Windows users have folders full of forgotten BMPs from the Paint era or from scanner output. Batch converting them to JPG can free 10 to 50 GB of storage.
Emailing a scanned document
Scanner software often defaults to BMP output, which can exceed the 25 MB email limit on a single page. Converting to JPG fits dozens of pages into one email.
Uploading a legacy screenshot to a modern platform
A BMP screenshot from Windows XP can be 5x over the upload size limit on many modern platforms. Converting to JPG typically solves the problem.
Standardizing an archive of mixed image formats
If you are normalizing an old photo library with BMPs, TIFFs, and PNGs mixed in, JPG at quality 90 is a sensible universal target.
Frequently asked questions
- Will I lose noticeable quality?
- At quality 85 or higher, the loss is imperceptible on photographic content. On BMPs containing text, sharp edges, or flat color regions, you may see minor compression artifacts — consider PNG as an alternative in those cases.
- How much smaller will the JPG be?
- On typical photographic BMPs, expect 20 to 50 times smaller. A 5 MB BMP becomes a 100 to 250 KB JPG. On heavily compressible content like flat-color graphics, the savings can be even larger.
- What happens to transparency?
- BMP has optional alpha support in 32-bit mode, but JPG does not support transparency at all. Any transparent pixels are replaced with a solid white background in the JPG output.
- Can I keep my BMP files losslessly smaller?
- Yes — convert to PNG instead of JPG. PNG is lossless and typically produces a file 50 to 70 percent smaller than the BMP, with no quality change at all. Use PNG when lossless matters; use JPG when size matters more than exact fidelity.
- Is my BMP uploaded to any server?
- No. The conversion is 100 percent client-side through the HTML5 Canvas API. Your BMP is decoded in your browser, encoded locally as JPG, and handed back to you as a download. No server involvement.