Image compressor
Tell it the size limit you have been given. It finds the best-quality image that fits under it.
JPG, PNG, WebP and HEIC. Your file is processed on your device.
How do I compress an image?
What this compressor does differently
Almost every image compressor gives you a quality slider and lets you guess. You drag it to 60, export, check the size, find it is still too big, drag it to 45, and repeat. The number you actually care about — the one the upload form gave you — never appears in the process at any point.
FileBelow takes that number as the input. You type in the maximum, and it works backwards to the best image that fits.
Why it searches two things instead of one
A photograph’s file size is governed by two things: how many pixels it contains, and how much data the encoder spends on each one. Most tools vary only the second. Squeezing quality alone at full resolution is what produces the blocky squares and smeared texture people recognise as “over-compressed”.
Giving up some resolution instead often preserves far more of the picture at the same file size. Which trade is better depends on the image, so FileBelow encodes candidates at several resolutions, scores each against your original using a structural similarity measure, and keeps the winner. At generous limits that is usually the full-resolution image and nothing is given up at all.
Common questions
Is it free?
Yes. There is no account, no upload quota, no watermark and no paid tier.
Are my images uploaded?
No. Compression runs in your browser using your own device. There is no server that could receive an image — the site is entirely static. You can confirm this in your browser’s network tab, and the tool keeps working if you go offline after the page has loaded.
What formats can it compress?
It reads JPG, PNG, WebP and HEIC, and writes JPG, PNG or WebP. HEIC is the format iPhones use by default, which most upload forms will not accept.
Does compressing lose quality?
Any lossy compression discards some information — that is how the file gets smaller. The question is whether you can see it. At generous limits the loss is invisible. At tight limits it is not, which is why the result panel tells you the dimensions it chose and gives an honest estimate rather than claiming everything went perfectly.
What happens if my target is impossible?
It says so, and tells you what would work instead. If a 4000-pixel-wide photo cannot reach your limit, FileBelow finds dimensions that can, verifies them by actually encoding at that size, and offers them as a button. It never silently breaks the rule you asked for.
Does 1 MB mean 1,000,000 bytes or 1,048,576?
FileBelow treats 1 MB as 1,000,000 bytes. Upload forms disagree about this, and the decimal figure is the smaller of the two, so a file that meets it satisfies both readings. If a form has rejected a file you were sure was under the limit, this is a likely explanation.