How to Compress BMP Files on MacSave 90-98% storage space without losing quality
What Is BMP (Bitmap Image File)?
BMP (Bitmap) is an uncompressed raster image format originally developed by Microsoft for Windows. BMP files store each pixel individually with no compression, resulting in very large file sizes. While rarely used intentionally today, BMP files still appear in legacy software, screenshots from older systems, and some specialized applications.
Why Are BMP Files So Large?
BMP files are the largest common image format because they store raw pixel data with zero compression. Every single pixel uses 3 bytes (24-bit color) or 4 bytes (32-bit with alpha). A 1920x1080 image in BMP format is approximately 6MB, while the same image as JPG would be 200-500KB.
Typical BMP Compression Results
Before
2-50MB per image
After
100KB - 5MB per image
90-98%
Smaller
Compression Ratio
10:1 to 50:1
Codecs
Uncompressed, RLE (rare)
How to Compress BMP Files on Mac (Step by Step)
Follow these steps to compress your BMP files using MediaOptim on macOS:
Open MediaOptim
Launch MediaOptim. It reads BMP files and converts to modern, efficient formats.
Add BMP files
Drag your BMP images into the app. MediaOptim shows the massive space savings potential.
Choose output format
Select JPG for photos, PNG for graphics with transparency, or WebP for web use. Any modern format is dramatically better than BMP.
Convert
MediaOptim converts BMP files to your chosen format. The process is virtually instant.
Reclaim space
Review and save. BMP conversions show the most dramatic savings of any format: typically 90-98% reduction.
BMP Technical Details & Compression Tips
Best Quality Settings
Convert to JPG at quality 90 for photographs (95%+ savings) or PNG for graphics with transparency (70-80% savings). There is virtually no reason to keep BMP format on modern systems.
When to Convert vs Compress
Always convert BMP to a modern format. JPG for photographs, PNG for graphics needing transparency or exact pixel preservation, WebP for web use. The savings are dramatic with no practical downside.
Technical Specifications
- Completely uncompressed pixel data (no compression algorithm)
- File size = width x height x bytes per pixel + header
- 1920x1080 at 24-bit = 5.93MB (vs ~300KB as JPG)
- Some BMP variants support RLE compression (rarely used)
- Converting to any modern format saves 90-98% with identical or better quality
Frequently Asked Questions
How do I compress BMP files on Mac?
Convert BMP to JPG, PNG, or WebP using MediaOptim. BMP is uncompressed, so converting to any modern format saves 90-98% of the file size with no quality loss.
Why are BMP files so large?
BMP stores every pixel with zero compression. A 1920x1080 image uses 6MB as BMP vs 200-500KB as JPG. The format simply has no compression algorithm.
Should I keep any files as BMP?
No. There is no practical reason to store images as BMP on modern systems. PNG provides lossless quality at 70-80% smaller size, and JPG provides 95%+ savings for photos.
What is the best format to convert BMP to?
JPG for photographs (95%+ savings), PNG for graphics needing exact pixel preservation or transparency, WebP for web use. All are dramatically more efficient than BMP.
Will converting BMP to JPG lose quality?
JPG is lossy, so technically yes, but at quality 90+ the difference is invisible. For truly lossless conversion, use PNG instead, which still saves 70-80% over BMP.
Compress Your BMP Files Now
Save 90-98% on your BMP files. No quality loss. Everything stays on your Mac.
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