JPG Compressor: Shrink Photo File Size Without Losing Quality

Drop your image into the tool and download the smaller version in seconds — nothing leaves your browser.

JPEG doesn't compress an image the way a ZIP file compresses text. A ZIP file has to be perfectly reversible — every byte has to come back exactly as it went in. JPEG doesn't play by that rule. It's a *lossy* format, which means it deliberately throws away information the human eye is bad at noticing, and keeps the information your eye is good at noticing.

Two things get discarded first: **Color detail** and **Fine texture in busy areas**. Human vision is far more sensitive to changes in brightness than changes in color. JPEG encoders exploit this by storing color information at lower resolution than brightness information — a technique called chroma subsampling.

Every JPG compressor gives you some version of a quality slider or percentage. Here's what it's actually doing: it controls how aggressively the encoder simplifies each block before writing it to the file. Higher number, less simplification, bigger file. Lower number, more simplification, smaller file — and past a certain point, visible artifacts.

As a working range: **90-100:** Barely any visible difference from the original, and barely any file size savings either. **75-85:** The sweet spot for most web and email use. Files typically drop 50-70% from the original with no artifacts visible at normal viewing size.