JPEG is the format of almost every photo you take, and it is already compressed. That is why the question is never only "how small?" but "how small before it looks worse?". This page helps you compress JPEG photos with that question in mind.
Format is set to JPG, so whatever you open comes out as a JPG that any device or site accepts. You set the Quality, compare the result with the original side by side, and save only when you are happy. This JPEG compressor runs in your browser, nothing is uploaded, and it is free.
Whether you want to reduce JPEG file size for a website, an email or an upload form, the method is the same: find the lowest quality that still looks right to you, and make the photo no bigger in pixels than it will be shown.
How to compress a JPEG, step by step
- Press Select images and choose your JPG photos. One photo is shown on the stage; the others wait in the strip below it.
- Under Compress by, keep Quality, and drag the Quality slider or pick a chip.
- Look at the split view: Before on the left, After on the right. Drag the divider over the part of the photo you care about.
- Check the Result line, for example JPG · 4032 × 3024 · 612 KB · 71% smaller.
- Press Compress and save. The file name ends in _compressed.jpg, so the original is kept.
The size in the panel is not a guess. The photo is really encoded at your setting, the same way the saved file will be, so the Original and Result bars show exact numbers. Until the first measure arrives they carry a "≈".
This page opens any picture the image compressor takes, not only JPGs. A PNG, a WebP or an iPhone HEIC photo is saved as a JPG here. Transparent areas become white, because JPG has no transparency. If you only want to turn an iPhone photo into a JPG, HEIC to JPG does just that, with three simple Quality choices. For a PNG, there is a page to convert PNG to JPG as well. A PDF does not open here: convert PDF to JPG first, then compress the pages.
JPEG quality settings, explained
JPEG quality is a number from 1 to 100. It is not a percentage of anything: it tells the encoder how much fine detail it may simplify. Higher keeps more detail and makes a bigger file. The slider starts at 75, and three chips cover most needs.
| Quality | What you usually see | Use it for |
|---|---|---|
| 90 (Best) | Very hard to tell from the original | Photos you will edit again, print, or keep as a good copy |
| 75 (Balanced) | Clean on screen; tiny changes in fine texture at 100% | Websites, email, sharing, most everyday photos |
| 50 (Smallest) | Softer detail, some blockiness in smooth areas | Thumbnails, previews, and pictures where size matters most |
| Under 40 | Visible blocks and smudged edges | Only when a strict size limit leaves no choice |
Going from 90 down to 75 usually saves a lot of space for little visible change, while going from 75 down to 50 saves less and costs more of the look. That is why Balanced is a good place to start. Every photo is different, though: a sharp landscape full of leaves needs more quality than a soft portrait.
For how JPEG decides which detail to drop, and why a PNG of the same photo is so much bigger, read about lossy vs lossless compression.
Check the result at 100% before you save
On a fitted view, almost any quality looks fine, because the photo is shrunk to the screen. Press 100% under the picture, or use the + key, and compression shows up where it is hardest to hide. Then use Hold to compare, or the Space key, to flick between the original and the result.
- Blue skies and plain walls: look for bands and small square blocks.
- Edges against the sky, such as roofs and branches: look for a faint shimmer or halo.
- Text and signs in the photo: look for smudged letters.
- Skin and fabric: look for a waxy, smoothed look where there was texture.
If you see any of these, raise the Quality a few points and look again. Once the measure finishes, the Result line shows the new size, so you see the price of each step in KB.
Reduce JPG file size to a KB limit, or for many photos
When a form or site sets a limit, pick Target size under Compress by: it is the JPG size reducer for upload forms that ask for a photo under a set number of KB. Set the size, and the tool tries up to 8 quality levels to find the best one under it. A KB here is 1,000 bytes, so the result also passes a form that counts 1,024. If the lowest quality is still too big, Allow a smaller picture size shrinks the photo in pixels as well. For a common case, see compress an image to 200 KB.
To compress JPG photos in a batch, select up to 100 at once. Each one gets the same settings, the button reads Compress 24 pictures or however many you chose, and Save all as ZIP keeps them together. The done screen lists every photo with its new size and how much smaller it is.
Photos are often far larger in pixels than they will be shown. Switch on Also make it smaller in pixels and set a Longest side, such as 1920, and the file shrinks a lot before quality even comes into it. The photo keeps its shape and is never enlarged.
When a JPEG will not shrink much
Sometimes the Result line says only 5% smaller, or the panel warns that the result is bigger than the original. That usually means the JPEG was compressed hard already, for example by a messaging app. Saving it again at a high quality cannot get the lost detail back, and it may need more bytes to describe the blocks that are already there.
- Lower the Quality until the size drops, and check at 100% that it still looks right.
- Make it smaller in pixels, which helps every photo.
- Switch Format to WebP, which is usually smaller than JPG for the same look, if the place you send it accepts WebP.
- For screenshots and graphics with large flat areas, try Compress PNG instead. The guide to JPEG vs PNG explains why photos and screenshots suit different formats.
Each time you compress a JPEG, a little more detail goes, so always start from the best copy you have rather than a file that has been compressed before. Your original is never changed here.
Compress your JPEG now
To compress JPEG photos well, start at Balanced, check the result at 100% with Hold to compare, and move the Quality until the size and the look both suit you. For a size limit, use Target size; for big photos, make them smaller in pixels too.
Select your photos above and press Compress, or select up to 100 at once to compress JPG photos in one batch. It is free and private.
