Image Compressor

Lossy vs lossless: how image compression actually works

Lossless compression shrinks a file by storing the same pixels more efficiently — nothing is thrown away, and the image is bit-for-bit identical when opened. It's safe but limited: savings on photos are usually modest. Lossy compression discards visual detail your eye is unlikely to notice — subtle color variations, high-frequency texture — and that's where the dramatic 70–90% size reductions come from. The quality slider on this tool controls how aggressive that trade-off is. The sweet spot for most photos is 75–85%: files shrink to a fraction of their original size while looking indistinguishable at normal viewing sizes.

Choosing a quality setting

• 85–90% — near-perfect quality for portfolio images, product photography, and print previews.
• 75–85% — the default range for website images and blog posts; visually clean at a fraction of the size.
• 60–75% — thumbnails, avatars, and previews where small size matters more than close inspection.
• Below 60% — only for very small display sizes; expect visible artifacts on edges and gradients.

Target sizes worth aiming for

As a rule of thumb: hero and banner images should land under 200 KB, in-content images under 100 KB, and thumbnails under 30 KB. Oversized images are the single most common cause of slow pages and poor Largest Contentful Paint scores, and email providers often reject attachments over 20–25 MB — compressing a batch of photos before sending routinely cuts a 40 MB email down to a few megabytes. Everything here happens locally in your browser, so you can compress sensitive screenshots or client photos without them ever touching a server.