Compress image to 500KB
Drop a photo in, and it comes back under 500KB at the best quality that still fits. Everything runs inside this browser tab — your files are never uploaded.
Who asks you to compress image to 500kb
A practical ceiling for a hero image on a page that needs to score well on Core Web Vitals. Above this, Largest Contentful Paint starts to suffer on mobile connections.
Whatever the reason for the limit, the practical problem is identical: a modern phone camera produces files of several megabytes and the form in front of you will not take them. What you need is not "smaller" but "under this specific number", which is exactly what a plain quality slider cannot give you.
Resolution you keep at 500KB
A useful rule of thumb: a typical photograph at moderate quality costs roughly an eighth of a byte per pixel. Working backwards from 500KB, the practical ceiling is around 4,266,667 pixels — approximately 2530 by 1690. Stay at or below that and the encoder has enough budget to look clean. Push well past it and you are spreading a fixed budget over more pixels, which is where blocking and smeared detail come from.
This is an order-of-magnitude guide, not a promise, because content matters enormously. A flat product shot, a screenshot or a scanned signature compresses several times better than the estimate. A noisy night scene or dense foliage compresses considerably worse, since noise is incompressible by design. When you compress image to 500kb here the tool measures the real encoded file rather than estimating, so the answer is honest for your specific image.
If the estimate says your photograph is well past that pixel budget, the better move is to reduce the dimensions deliberately before you compress image to 500kb, choosing what to lose rather than letting the encoder decide. A half-resolution image at a generous quality setting almost always looks better than a full-resolution one squeezed to the same number of bytes.
How this tool can compress image to 500kb exactly
Most compressors give you a quality slider and let you find out afterwards how big the file turned out. That is the wrong way round when you have a hard ceiling. This tool works backwards from the number: you ask it to compress an image, and it searches for the encoder setting that lands just underneath.
The search is a binary search over the JPEG or WebP quality parameter. It encodes at the midpoint of the remaining range, checks the byte count against 500KB, and moves the range accordingly. Nine passes narrow the setting far finer than the eye can resolve, and every pass keeps the best result that fit — so what comes back is the highest quality version that still fits, not the first one that happened to work. Nine passes is also fast enough that you can compress image to 500kb, look at the result, change the number and run it again without ever waiting on a progress bar.
When quality alone cannot get there, the tool reduces pixel dimensions in steps and searches again. That order matters: dropping quality first preserves your framing, while shrinking first throws away detail no quality setting can recover. Final dimensions are listed next to the file whenever a resize was needed, so an attempt to compress image to 500kb never quietly returns something smaller than you asked for without saying what it gave up to get there.
JPG, PNG or WebP at 500KB?
500KB is roomy enough that the format genuinely matters. WebP reaches the same visual quality as JPG at roughly a quarter fewer bytes, so choosing it leaves more of your detail intact for the same file size. Every current browser renders WebP, and it is accepted by most modern upload forms.
Stay with JPG if the file is going into something old or unpredictable — a government portal, an applicant tracking system, a desktop application that was last updated a decade ago. Those systems frequently validate by file extension and will reject a WebP without explaining why. PNG remains a poor choice at this size for photographs, though it is fine for screenshots and flat-colour graphics, which compress losslessly far better than photos do.
Your files never leave the browser
Nothing you drop onto this page leaves your device. The image is decoded, re-encoded and handed back entirely inside the browser tab. There is no upload, no queue, and no temporary copy sitting on someone else's disk waiting for a retention policy to delete it.
That matters more than it sounds. The files people most often need to shrink are the ones they should be most careful with: passport scans, signatures, identity documents, medical forms. Handing those to an unknown server in exchange for a smaller file is a poor trade. Because the work is local, you can shrink a file with the network disconnected and get the same result.
It also means there is no queue to wait in and no daily allowance to run out of. Server-side compressors have to ration free use because every file costs them CPU time; here the CPU is yours, so you can compress image to 500kb as many times as you like, on as many files as you like, without an account.