Guide

How to Compress an Image (Without Ruining It)

Image compression means encoding the same picture in fewer bytes. There are two ways to do it: lossy compression (JPG, WebP) discards detail your eye barely notices, and lossless compression (PNG) packs the data more efficiently without discarding anything.

Step 1: pick the right format

Photos compress best as JPG or WebP. Screenshots, logos and graphics with flat colors compress best as PNG. Using the wrong format is the most common reason files stay huge.

Step 2: choose a sensible quality level

For JPG, quality values between 70 and 85 are the sweet spot for web use. Below 60 you start to see blocking around sharp edges. WebP looks better than JPG at the same quality number.

Step 3: compress and compare

Always compare the result against the original at 100% zoom before committing. If the difference is invisible, the compression is free. If you need an exact file size - say 100KB for an upload form - use a tool that iteratively searches for the best quality that fits, instead of guessing with a slider.

What not to do

Do not compress the same JPG repeatedly; every save is another lossy generation. Keep the original and compress a fresh copy each time.