Compress an image
Make photos smaller with a quality control you can actually see the effect of. Nothing leaves your device.
Drop JPG, PNG, WebP, HEIC, AVIF, GIF, BMP files here or paste from the clipboard.
Your files are processed on this device. Nothing is uploaded.
Compressing to a number
Most of the time the requirement isn’t "smaller", it is "under 100KB", because a form said so. That is a solvable problem rather than something to nudge a slider towards: file size falls as quality falls, so a handful of encodes finds the highest quality that fits. The tool does six or seven and reports where it landed.
The judgement call is what to do when quality alone can’t reach the target. Dropping to quality 10 on a full-resolution photo produces something technically under the limit and visually ruined. So there is a floor at around 45 and below it the tool reduces the dimensions instead, using the measured bytes per pixel to work out how far. A 500 pixel image that looks correct beats a 4,000 pixel one that doesn’t.
Sizes are decimal here: 100KB means 100,000 bytes rather than 102,400. A file under the decimal figure is under the binary one too, so the result clears the limit whichever convention the system on the other end uses.
Where the savings actually come from
There are three levers and most people only reach for the third:
- Dimensions. Halving the width quarters the pixel count. Nothing else comes close. A photo that’ll be displayed at 800 pixels doesn’t need to be 4000.
- Format. WebP at the same visual quality is typically 25 to 35% smaller than JPG. Switching format costs nothing in quality terms; it is the free lever.
- Quality. The slider. Useful, but the one with a visible cost, which is why it belongs last rather than first.
How to tell when you have gone too far
Look at three places in the image rather than at the whole thing. Edges between strongly different colours pick up a faint halo first. Smooth gradients, a clear sky most obviously, break into visible bands. Fine repeated detail, such as hair, foliage or fabric texture, turns mushy. If none of those three has changed at 100% zoom, the compression is free as far as a viewer is concerned.
Why the file never leaves your device
Compression is arithmetic on pixels and your browser is perfectly capable of arithmetic. There is no technical reason to send a photograph to a server, wait and download it back and several reasons not to: it is slower, it puts your photograph on someone else’s disk and it breaks the moment you’re offline. This page does the work locally, so a batch of fifty photos never touches the network.
Common questions
How do I compress to an exact file size?
Switch the tool to "a file size" and type the number. It then searches for the highest quality that fits under your target, usually in six or seven encodes and tells you what it settled on. If quality alone can’t get there it reduces the dimensions rather than dropping below a quality floor, because a smaller sharp image is more useful than a full-size smeared one.
What quality setting should I use?
For photographs, 75 is the usual sweet spot and 60 is still acceptable for most web use. Below about 50 you start seeing blocking around high-contrast edges. For screenshots and anything with text or flat colour, lossy compression is the wrong tool entirely: use PNG or WebP, because JPG turns crisp text into a smear of artefacts.
Why did compressing my PNG make it bigger?
Because a browser’s PNG encoder isn’t trying to be clever. PNG is lossless, so the only saving available is smarter prediction and dictionary choices and a browser skips that work. Dedicated tools like pngquant and oxipng do it properly. If the goal is a smaller file rather than specifically a PNG, saving as WebP typically cuts it by half or more with transparency intact.
Is this lossless?
No and it shouldn’t be. Compressing to JPG or WebP throws away detail your eye is bad at noticing, which is exactly where the savings come from. If you need the pixels untouched, the only honest answer is to leave the file alone or to use the EXIF remover, which shrinks a file slightly by deleting metadata without touching the image.
Can I compress the same file twice?
You can, but don’t. Each lossy pass compounds the last one’s artefacts, because the encoder is now trying to faithfully reproduce compression damage. Always compress from the original rather than from a previously compressed copy and keep the original somewhere.
What does capping the width do?
It scales the image down so it is no wider than the number you set, keeping the proportions. This is usually the single biggest saving available: a 4000 pixel wide phone photo displayed in a 800 pixel column is carrying twenty-five times more pixels than it can show. Capping the width first, then compressing, beats compressing hard at full size.
Compress to a specific size
Each of these opens the tool with the target already set.
Guides
The other tools
All of them work the same way: the file is read in your browser and never uploaded.