BMP Compressor
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Supports: BMP
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Need help?How to Compress BMP Files
- Upload your BMP — Click "+ Add Files" or drag and drop your BMP images. Batch upload is supported.
- Choose compression method — Under "Image Compression," select "Quality Preset" with levels from High to Low, or "Specific file size" to target an exact size in Bytes, Kilobytes, or Megabytes with Smart Scaling enabled.
- Adjust resolution — Keep original dimensions, scale by percentage (1–100%), pick a preset (4320p down to 144p), or enter exact width/height in pixels or percent.
- Compress and download — Click "Compress" and download your smaller BMP files individually or all at once.
Why Compress BMP Files?
BMP (Bitmap) is an uncompressed raster format developed by Microsoft that stores every pixel's color value directly. This means a standard 1920×1080 image at 24-bit color depth takes up roughly 6 MB — compared to around 200 KB for the same image as JPG. While BMP preserves exact pixel data with zero compression artifacts, the massive file sizes make it impractical for email, web use, or storage-constrained workflows.
Compressing BMP files through resolution reduction and quality presets lets you keep the BMP format when required by specific software (legacy Windows applications, embedded systems, medical imaging) while dramatically cutting file size. For general use, consider converting to a more efficient format like PNG (lossless) or WebP (best compression).
BMP File Size by Color Depth
| Color Depth | Colors | 1920×1080 Size | Reduction vs 24-bit |
|---|---|---|---|
| 24-bit (true color) | 16.7 million | ~6.2 MB | — |
| 16-bit | 65,536 | ~4.1 MB | ~33% |
| 8-bit (indexed) | 256 | ~2.1 MB | ~66% |
| 4-bit | 16 | ~1.0 MB | ~84% |
| 1-bit (B&W) | 2 | ~0.25 MB | ~96% |
When to Keep BMP vs Convert
| Scenario | Recommendation |
|---|---|
| Legacy software requires BMP | Compress BMP with resolution reduction |
| Web publishing | Convert to WebP or JPG |
| Lossless archival | Convert to PNG |
| Print workflow | Convert to TIFF |
| Email attachment | Use "Specific file size" to target under 5 MB |
Frequently Asked Questions
Why are BMP files so large?
BMP stores every pixel's raw color data without any compression. A 1920×1080 image at 24-bit color requires 1920 × 1080 × 3 bytes = approximately 6.2 MB. Formats like PNG and JPG apply compression algorithms that reduce this dramatically while preserving visual quality.
Can I compress BMP without converting to another format?
Yes. XConvert reduces BMP file size by adjusting resolution — scale down by percentage, pick a preset resolution, or set exact pixel dimensions. You can also target a specific file size in KB or MB using the "Specific file size" option with Smart Scaling, which automatically adjusts dimensions to hit your target.
What quality preset should I choose?
"High" works well for most images, balancing quality and size. "Medium" and "Low" produce smaller files but may show visible quality reduction. For BMP specifically, resolution reduction is the most effective compression method since the format itself doesn't support lossy compression.
Should I convert BMP to another format instead?
For most use cases, yes. PNG offers lossless compression (same quality, much smaller files), JPG offers the smallest files for photos, and WebP provides the best overall compression. Keep BMP only when specific software requires it.
Is there a file size limit for uploads?
XConvert handles large BMP files with no sign-up required. You can upload multiple files at once for batch compression.
Does compressing BMP affect image quality?
Reducing resolution will reduce pixel dimensions, which affects detail at full zoom. The "Quality Preset" option controls the compression aggressiveness. For BMP files, the primary size reduction comes from resolution scaling since BMP doesn't support internal lossy compression like JPG does.