Resize MP4 files
Resizing is usually the biggest lever for reducing MP4 file size.
Last updated: 2026-03-18
To resize MP4 files, run npx optimo video.mp4 --resize <value>. Optimo supports three modes: percentage (50%), dimensions (w960), and target file size (150kB). Resizing reduces both dimensions and file size in one step — often more effective than compression alone.
Resize by percentage
Quick way to scale down when you don't know exact dimensions yet.
npx optimo video.mp4 --resize 50%
Resize by dimensions
Cap width or height to match how the asset is displayed.
npx optimo video.mp4 --resize w960
Use w for width and h for height.
Resize to a target file size
Useful for thumbnails and previews when you want predictable budgets.
npx optimo video.mp4 --resize 150kB
Start with a budget you can ship everywhere, then adjust based on quality.
MP4-specific tips
- Match the video width to the player size; oversizing wastes bandwidth.
- Shorten duration when possible; seconds matter more than codec tweaks.
- For background loops, consider converting to WebM and compare sizes.
Related pages
More video formats
Frequently asked questions
- How do I resize MP4 files?
- Optimo supports three resize modes: percentage (--resize 50%), dimensions (--resize w960 or --resize h480), and target file size (--resize 150kB). Run "npx optimo video.mp4 --resize <value>" to resize and optimize in one step.
- What is the best resize mode for MP4?
- Use dimensions (--resize w960) when you know the display size. Use percentage (--resize 50%) for quick scaling. Use target file size (--resize 150kB) for thumbnails and budgets. Resizing is usually the single biggest lever for reducing MP4 file size.