Image Compressor

Features

• A target size in KB, with binary search for the highest quality that fits
• A clear notice when the target cannot be reached, plus a suggestion to limit size
• Quality steps (92%, 80%, 65%, 50%) when you prefer to pick
• Limit the longest edge to 2560, 1920, 1280 or 800 pixels
• Shows before and after (12.3 MB → 2.1 MB, −83%)
• PNG sources become WebP, with the reason stated
• Nothing is uploaded — compression happens in the browser

How to use

1. Drop an image in
2. Enter a target size in KB, or pick a quality step
3. If it will not go small enough, set a max edge as well
4. The result shows the before/after; click Download to save

FAQ

Lowering the quality barely changed the size. Why?

Two cases. The source may be PNG, where quality does nothing at all — that is why it is converted to WebP here. Or the quality is already low (below 0.5), where each further step saves less and less while visibly softening the image. The effective lever then is size: going to 1280 or 800 pixels cuts the file several-fold and usually looks better than crushing the quality.

How is the target size computed?

Binary search. The tool encodes at the midpoint between the lowest quality (0.3) and 0.95, measures the result, and narrows the range — about seven attempts reach the highest quality under the target. Each attempt is a real encode, which is why it takes a few hundred milliseconds: there is no way to know the size without producing it.

It hit the target — can it look better?

The binary search already returns the highest quality that fits, so within that limit it is as sharp as it gets. For a sharper image, either allow a larger size or shrink the dimensions first — smaller dimensions fit a higher quality into the same budget.

Is the image uploaded?

No. Compression uses the browser's own canvas, entirely in local memory, and works offline.