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Compress JPG

Reduce JPG file sizes by 60–80% with no visible loss of quality.

How to compress JPG

Drop your JPG files onto the panel above and press Compress. Whole folders are fine, and the results download individually or as one ZIP.

Choose a quality preset before you press it — Balanced suits almost everything — or drag the slider for finer control. Afterwards, drag the before/after divider on the preview to compare the result against the original at full resolution, which is the only reliable way to judge whether a setting cost you anything worth keeping.

Everything runs inside this page as WebAssembly, so your files are never uploaded. That is why there is no size limit and no queue, and why the tool keeps working if you go offline.

How JPG compression works

JPG compression is lossy: the encoder converts the image into frequency components and stores the ones your eye relies on most precisely, while coarsening the fine, high-frequency detail it barely registers. Lowering the quality setting coarsens more of it.

Encoder: MozJPEG, Mozilla's encoder, with progressive output and trellis quantisation enabled — the same build Squoosh uses. It typically produces smaller files than a browser's built-in JPG save at identical quality.

How much smaller JPG files get

A camera or phone JPG at quality 75 typically loses 60–80% of its size — a 4 MB photo usually lands between 400 KB and 1 MB. JPGs that were already saved at a low quality save far less, because the detail has already been discarded.

Quality 75 is the practical default and 85 is generous. Above 90 the file grows quickly for detail almost nobody can see; below 50 blocking and colour banding become obvious in skies and smooth gradients.

When to convert instead

If the JPG is destined for a website, converting to WebP or AVIF saves considerably more than any amount of JPG quality tuning: roughly 25–34% for WebP and around 50% for AVIF at matched quality.

Frequently asked questions

Does compressing JPG reduce quality?

At quality 75–85 the difference is imperceptible for photographs, which is what visually lossless means — and the before/after slider lets you verify at full resolution before downloading. Quality 75 is the practical default and 85 is generous. Above 90 the file grows quickly for detail almost nobody can see; below 50 blocking and colour banding become obvious in skies and smooth gradients.

How much can JPG be compressed?

A camera or phone JPG at quality 75 typically loses 60–80% of its size — a 4 MB photo usually lands between 400 KB and 1 MB. JPGs that were already saved at a low quality save far less, because the detail has already been discarded.

How do I compress JPG to a KB limit?

Switch Compression to To a file size and type the limit, or start from a page with the target preset: 20 KB, 50 KB, 100 KB, or 200 KB. The tool searches quality levels automatically and keeps the best result that fits.

Compress JPG or convert it?

If the JPG is destined for a website, converting to WebP or AVIF saves considerably more than any amount of JPG quality tuning: roughly 25–34% for WebP and around 50% for AVIF at matched quality.

Finish the job

Common follow-ups, one click from here. Your image stays on your device between tools.