How do I resize JPEG files?

Optimo supports three resize modes: percentage (--resize 50%), dimensions (--resize w960 or --resize h480), and target file size (--resize 150kB). Run "npx optimo photo.jpg --resize " to resize and optimize in one step.

What is the best resize mode for JPEG?

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 JPEG file size.

Resize JPEG files

Resizing is usually the biggest lever for reducing JPEG file size.

Last updated: 2026-03-18

To resize JPEG files, run npx optimo photo.jpg --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 photo.jpg --resize 50%

Resize by dimensions

Cap width or height to match how the asset is displayed.

npx optimo photo.jpg --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 photo.jpg --resize 150kB

Start with a budget you can ship everywhere, then adjust based on quality.

JPEG-specific tips

For hero images, cap width (`--resize w1920`) to avoid shipping huge originals.
For feeds and thumbnails, try `--resize 50%` or `--resize 200kB`.
Avoid repeatedly re-encoding the same JPEG; keep an original source.

Optimize JPEG Compress JPEG JPEG format guide

More image formats

Resize PNG Resize WebP Resize AVIF Resize HEIC Resize JPEG XL Resize GIF Resize SVG

Frequently asked questions

How do I resize JPEG files?: Optimo supports three resize modes: percentage (--resize 50%), dimensions (--resize w960 or --resize h480), and target file size (--resize 150kB). Run "npx optimo photo.jpg --resize <value>" to resize and optimize in one step.
What is the best resize mode for JPEG?: 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 JPEG file size.