What "without losing quality" really means
Worth being straight about this: any format that makes photographs meaningfully smaller is lossy, so data is always discarded. What people actually want is visually lossless — a file where the discarded data isn't data you could see anyway.
That's very achievable. JPEG and WebP encoders are designed around the limits of human vision: they preserve the edges and contrast your eye tracks, and spend fewer bits on subtle colour variation it doesn't. A photo saved at 85% quality is typically less than half the size of the same photo at 100%, and in normal viewing the two are indistinguishable.
The settings that matter
- Quality 85% (set above) — a large saving with no visible change on almost any photo. Below about 70% you start to see artefacts in sky, skin, and flat colour; below 50% it's obvious.
- Resize the dimensions — the biggest lever by far, and invisible if the image is still larger than it's displayed. A 4000px photo shown in a 1200px column loses nothing useful when resized to 1600px.
- Use WebP — typically 25–35% smaller than JPEG at matching quality. Choose it under Output if the file is for the web.
Combining a sensible resize with 85% quality usually shrinks a phone photo by 90% or more while looking the same on screen.
One caveat on WebP: every current browser can display WebP, but Safari still can't create it from a web page. If you're on Safari, this tool falls back to JPEG automatically and tells you it has — you'll still get a properly compressed file, just a slightly larger one. In Chrome, Edge and Firefox you get real WebP.
Where quality genuinely gets lost
Two habits do real damage:
Recompressing an already-compressed file. Each save throws away detail permanently, and the losses accumulate. Saving a JPEG at 85% five times looks noticeably worse than saving the original once at 85%. Always compress from the best original you have, not from a copy that's been through the process before.
Compressing the wrong kind of image with JPEG. Screenshots, logos, line art, and anything with sharp text or flat colour develop visible fringing around the edges. Those belong in PNG, which is lossless. JPEG and WebP are built for photographs.
When you need actually lossless
If the image will be edited further, printed large, or used as an archival master, keep a lossless original — PNG, or the untouched camera file. Compress copies for sharing and publishing, and leave the master alone. Lossless formats can still be made smaller, but the savings are modest compared with lossy compression.
Nothing is uploaded
Compression runs in your browser using your own device's processor. Nothing is transmitted, there's no queue, and the tool works offline once the page has loaded.
Frequently asked questions
Can an image be made smaller with no loss at all?
Truly lossless compression exists (PNG, WebP lossless) but the savings on photographs are small. The large reductions people want come from lossy compression, which can still be visually indistinguishable from the original.
What quality setting should I use?
80–85% suits almost every photo. Go to 90% for images that will be printed or edited further; below 70% only when a file size limit forces it.
Does resizing lose quality?
Only if you make the image smaller than it will be displayed. Reducing a 4000px photo to 1600px for on-screen use discards detail nobody could see.
Is WebP better than JPEG?
For the web, generally yes — around 25–35% smaller at the same visual quality, and every current browser can display it. Two caveats: Safari can't create WebP from a web page, so this tool falls back to JPEG there; and some older desktop software still won't open it. JPEG remains the safer choice for print workflows and unpredictable software.
Are my images uploaded?
No. Everything runs in your browser and nothing is sent to a server.