BMP (Bitmap) files are completely uncompressed image files used by older Windows software. They store every pixel without any compression, making them enormous — a 1920×1080px BMP file is around 6MB, compared to 200KB for the same image as JPG. Here is how to compress BMP files for practical use.
Why BMP Files Are So Large
BMP format stores raw pixel data with no compression. A 24-bit colour BMP at 1920×1080px needs 1920 × 1080 × 3 bytes = approximately 6MB. Modern web image formats like JPG, WebP, and PNG apply mathematical compression that reduces this by 90–97% with minimal visible quality loss.
How to Compress a BMP Image
The most effective way to "compress" a BMP is to convert it to a modern format. Visit imgresizr.com and upload your BMP file. Use the Convert tool to save it as JPG (for photos) or PNG (for graphics). You can also use the Compress tool after conversion to further reduce file size. A 6MB BMP will typically become a 150–400KB JPG or 500KB–2MB PNG, depending on image content.
BMP File Size Comparison
| Format | Typical Size (1920×1080) | Quality |
|---|---|---|
| BMP | ~6 MB | Lossless |
| PNG | 0.5–3 MB | Lossless |
| JPG (85%) | 0.1–0.5 MB | Near-lossless |
| WebP | 0.1–0.4 MB | Near-lossless |
When Should You Keep BMP Format?
BMP is only needed for: legacy Windows application compatibility, some print workflows that require raw bitmap data, and specific hardware or embedded systems. For virtually all other uses — web, email, social media, documents — convert BMP to JPG or PNG to reduce file size by 95%.
Convert and compress BMP images for free at imgresizr.com — instant results, no software download required.