Image Compressor

Image compression: how to shrink photos without ruining them

Why compress images?

Cameras and phones produce images far larger than screens or websites need. A single phone photo is often 3–8 MB; a page with ten of them takes half a minute to load on a normal connection. Compressing images before you upload or send them makes websites faster, emails smaller, and cloud storage cheaper.

How lossy compression works (and what the quality slider does)

JPEG and WebP compression works by throwing away detail the human eye barely notices. The quality setting controls how aggressive that trade-off is:

• High quality (80–100%): nearly indistinguishable from the original, modest size reduction.
• Medium (60–80%): the sweet spot for web use — much smaller, still looks great on screen.
• Low (below 60%): dramatic size cuts, but you may see blocky artifacts around edges and text.

PNG is different: it is lossless, so 'compressing' a PNG mostly means re-encoding it efficiently or converting it to a lossy format. For photos, JPEG or WebP will always be much smaller than PNG.

Choosing the right format

A good rule of thumb: photos go to JPEG or WebP, screenshots and logos stay PNG.

Practical targets

• Email attachments: keep each image under ~500 KB.
• Website hero images: 100–300 KB at 1600–2000 px wide.
• Thumbnails and avatars: under 50 KB.
• Documents and scans: medium quality is usually plenty.

This tool also lets you cap the maximum dimension, so a 4000-px photo can be downscaled and compressed in one step — resizing is often a bigger win than quality alone.

Why compress locally?

Most online compressors upload your images to a server, process them there, and let you download the result. This tool runs the compression in a Web Worker on your own device. Photos of people, IDs, documents, or anything private never leave your computer — and it works offline once the page has loaded.