Most images are far bigger than the job requires. A photo straight off a phone is routinely four or five megabytes, and the version that ends up on a website, in an email or in a chat needs a fraction of that to look identical. Compression is just deciding how much of the file you were never going to see anyway.
This compressor re-encodes your image at a quality you choose and tells you exactly what it saved before you download it. It runs inside this tab, so the photo is never uploaded and never sits on a server waiting its turn.
How to convert your file to the new format
- Add your image. Drag a JPG, PNG or WebP onto the box above, or click to browse.
- Set the quality. The slider is the whole tool. 82 is the default because it is roughly where people stop being able to tell. Drag down until you can see the difference, then go back a little.
- Download. The compressed image downloads with the saving shown in kilobytes, so you can judge whether the trade was worth it.
Why the same setting saves 80% on one image and 5% on another
Compression exploits predictability. A photograph of a face is full of gradual transitions that an encoder can approximate cheaply, which is why a five megabyte photo drops to a few hundred kilobytes with no visible change. A screenshot of text is the opposite: thousands of hard, unpredictable black-to-white edges, each of which the encoder has to spend bytes on or visibly ruin.
So the honest answer to how much you will save is that it depends entirely on what is in the picture, and any tool promising a fixed percentage is guessing.
Frequently asked questions
- Does compressing lose quality?
- Yes. That is the mechanism: JPG compression works by discarding detail it predicts you will not miss, and more compression means more discarded. At 82 the loss is essentially invisible on a photograph. The reason the saving is worth it is that the discarded detail was information your eye was never going to resolve.
- What quality should I actually pick?
- For photos on a website, 75 to 85. For an email attachment where size matters more than perfection, 60 is usually still fine. Above 90 you are adding a lot of bytes for a difference almost nobody can see, and below 50 you will start noticing blocky patches in skies and smooth gradients.
- Why did my PNG barely get smaller?
- Because PNG is already very good at what your image contains. Compression saves the most on photographs, where there is continuous detail to throw away. On a screenshot, a logo or a chart with large areas of flat colour, PNG's lossless compression is already near optimal, and squeezing it further mostly degrades the edges without saving much. If it is not a photograph, try converting to WebP instead.
- Is my photo uploaded to a server?
- No. The image is decoded, redrawn and re-encoded by your browser's own canvas engine. It is never transmitted, which means there is no copy of your photo on our side, no retention policy to read, and nothing to be leaked in a breach.
- Can I compress without losing anything at all?
- Not with this tool, and not meaningfully with any tool that produces a much smaller file. Truly lossless compression exists but typically saves 10 to 20 percent rather than 80. If you need the original pixels preserved exactly, keep the original.