JPEG Compressor

Reduce JPEG image file size while preserving quality.

JPEG compression is lossy: the encoder throws away detail your eye is unlikely to notice, then stores what remains far more compactly than a raw bitmap. That trade is why a 6 MB camera photo becomes a 400 KB web image with no visible difference — and also why the details you discard never come back.

What the quality setting actually changes

A JPEG encoder splits the image into 8×8 pixel blocks and describes each block as a sum of frequency patterns. High-frequency detail — fine texture, sharp edges, noise — is stored with the least precision, because that is where human vision is least sensitive. The quality setting controls how aggressively that precision is dropped.

  • Quality 80–90 is usually indistinguishable from the original at normal viewing size, at roughly a quarter of the file size.
  • Below about quality 60, flat areas start to show 8×8 blocking and sharp edges pick up a halo of "mosquito noise".
  • Photographs with lots of texture compress well; screenshots of text compress badly, because text is nothing but sharp edges.

Every re-save costs you something

Compression artifacts are baked into the pixels, so opening a compressed JPEG and saving it again compresses artifacts that are already there. Do it repeatedly and the image degrades visibly — the generational loss that makes heavily reshared images look muddy. Always compress from the highest-quality original you have rather than from a copy that has already been through the process.

When JPEG is the wrong format

JPEG has no transparency and handles flat colour and hard edges poorly. If your image is a logo, a screenshot, a chart, or anything with a transparent background, a compressed PNG will usually be both smaller and sharper. JPEG earns its place on photographs and photographic textures, where its assumptions about human vision hold.

  • Photographs, product shots, hero images → JPEG.
  • Logos, icons, UI screenshots, flat illustrations → PNG.
  • Anything that needs a transparent background → PNG, never JPEG.

How small does it actually need to be?

Pick a target from the constraint you are actually under, not from a round number. A photo emailed as an attachment only needs to clear the mail provider's limit. A hero image on a landing page is competing for Largest Contentful Paint and wants to be as small as it can be while still looking sharp on a high-density display. A form that rejects uploads over a fixed size gives you the target directly.

Frequently asked questions

Does compressing a JPEG reduce its quality?
Yes — JPEG is a lossy format, so some detail is always discarded. At moderate settings the loss is invisible at normal viewing size while the file gets several times smaller. The loss only becomes obvious when you compress aggressively, or when you compress a file that has already been compressed several times.
Why did my file get bigger after compressing it?
That usually means the original was already well optimized, and re-encoding it added data rather than removing it — for example when a low-quality JPEG is re-saved at a higher quality setting. If the source is already small for its dimensions, resizing it is a better lever than compressing it again.
Does compression remove EXIF and GPS data?
Re-encoding an image drops most of the metadata that was attached to the original file, including camera settings and any GPS coordinates. That is helpful if you are about to publish a photo taken at home, but it also means you should keep your original if the metadata matters to you.
Can I compress several JPEGs at once?
Yes. Add multiple files and they are processed together, then downloaded individually or as a single archive.
What is the difference between compressing and resizing?
Compressing keeps the pixel dimensions and stores those pixels less precisely. Resizing reduces the pixel dimensions themselves. For a photo that is far larger than the space it will be displayed in, resizing first and then compressing gives a much smaller file than compressing alone — see the image resizer.

What to do next

This tool is free. When you need more than file housekeeping, these pick up where it stops.

Bulk Image Upscale Compressed a photo that was already small? Upscaling rebuilds detail instead of stretching the pixels you have left.Background Removal Cutting the subject out drops everything behind it — often a bigger saving than compression, with a cleaner result.AI Image Editor Fix the image itself — lighting, distractions, unwanted objects — instead of only making the file smaller.