BMP vs JPG: File Size, Quality, and When to Use Each
Published on March 29, 2026
BMP (Bitmap) stores raw, uncompressed pixel data. JPG (JPEG) uses lossy compression to shrink files dramatically. A 1920x1080 BMP photo is roughly 6 MB. The same image saved as a JPG at high quality is around 300-500 KB. That 10-20x size difference is the core tradeoff: BMP preserves every pixel exactly, while JPG discards data your eyes are unlikely to notice.
Image Quality
BMP files are pixel-perfect. No compression artifacts, no quality loss, no generation degradation. Every pixel is stored exactly as the original. JPG compression works by grouping pixels into 8x8 blocks and approximating color values, which introduces artifacts, especially around sharp edges and text. At high quality settings (90-95%), these artifacts are barely visible. At low quality (below 60%), you get obvious blocky patches and color banding.
File Size
BMP files are enormous by modern standards. A 24-bit BMP stores 3 bytes per pixel with no compression. For a 12-megapixel photo, that is roughly 36 MB. JPG at quality 85 compresses that same image to about 2-4 MB. For web use, email attachments, or storage, BMP is completely impractical. JPG was specifically designed to solve this problem.
Compatibility and Use Cases
Both formats are universally supported. Every operating system, browser, and image editor opens BMP and JPG files. However, BMP has no practical use on the web. No website serves BMP images because the file sizes would destroy page load times. JPG is the default format for photos on the web, in messaging apps, and on social media. BMP still appears in Windows system resources, legacy software, and some industrial imaging applications where uncompressed data matters.
Color Depth and Features
BMP supports 1-bit (black and white), 4-bit, 8-bit, 16-bit, 24-bit, and 32-bit color depths, including alpha transparency in 32-bit mode. JPG only supports 24-bit color (16.7 million colors) with no transparency. Neither format supports animation. If you need transparency, PNG is the better choice over both BMP and JPG.
Which to Choose
Use JPG for photos, web images, and any situation where file size matters. Use BMP only when you need uncompressed pixel data for technical applications, or when working with legacy software that requires it. For everything else, JPG is the right format. If you need lossless quality without the massive file sizes, consider PNG instead.
Need to convert between image formats? Try our PNG to JPG converter or Image Resizer. For more format comparisons, see BMP vs PNG and RAW vs JPEG.