3/16/2026
Reduce 4K video file size by 60-80% with minimal quality loss. Includes CRF settings and codec comparison.
How to Compress 4K Video Size
4K videos are beautiful but huge. Here's how to compress them effectively.
File Size Reality
A minute of 4K can be several gigabytes. Compression is essential for:
- Storage savings
- Faster uploads
- Web delivery
Recommended Command
ffmpeg -i 4k_input.mp4 -c:v libx264 -crf 23 -preset fast -c:a aac -b:a 128k -pix_fmt yuv420p 4k_output.mp4
This typically reduces size by 60-70% with minimal visible quality loss.
Compression Methods
CRF Method (Recommended)
ffmpeg -i 4k.mp4 -c:v libx264 -crf 23 -preset fast output.mp4
HEVC (H.265) - Better Compression
ffmpeg -i 4k.mp4 -c:v libx265 -crf 23 -preset medium output.mp4
H.265 gives 30-50% better compression than H.264.
CRF Values for 4K
| CRF | Quality | Size Reduction |
|---|---|---|
| 18 | Excellent | 30-40% |
| 23 | Good | 60-70% |
| 28 | Acceptable | 75-85% |
Downscale to 1080p
Massive savings by scaling down:
ffmpeg -i 4k.mp4 -vf "scale=1920:1080" -c:v libx264 -crf 20 output.mp4
Quick Reference
# Recommended
ffmpeg -i 4k.mp4 -c:v libx264 -crf 23 -preset fast -c:a aac compressed.mp4
# Maximum compression
ffmpeg -i 4k.mp4 -c:v libx264 -crf 28 -vf "scale=1920:1080" small.mp4
# High quality
ffmpeg -i 4k.mp4 -c:v libx264 -crf 20 -preset slow highqual.mp4
Compress 4K videos effectively!