Reduce image file size to exactly 40KB
At 40KB there is enough room that compression stops being a compromise for most images. The tool re-encodes on a canvas, lowering quality gradually until the file fits; a photograph typically retains around 460x340 pixels with loss that is hard to see at normal viewing size. It runs entirely in your browser.
A browser-based compressor that re-encodes an image until it falls under 40KB, a budget that holds roughly 460x340 pixels of photographic detail.
Related terms
At this budget the encoder can keep about 460x340 pixels at a quality level where artefacts are hard to spot unless you zoom in.
Around 460x340 pixels prints acceptably at roughly 1x1 inches at 300 DPI. Larger prints need a bigger budget.
WebP typically reaches the same target with more detail preserved than JPEG, where the receiving system accepts it.
Compression runs on your own device using the Canvas API. There is no upload step and no server involved.
Compress Image to 40KB sits where compression stops hurting. A photograph keeps roughly 460x340 pixels and the loss is hard to see without zooming in, which makes it a common cap for document uploads.
The image is decoded, drawn to an offscreen canvas and re-encoded. Quality is stepped down and measured against the 40KB ceiling on each pass; dimensions are only reduced if quality reduction alone cannot reach the target, which is uncommon at this size.
Document scans, ID photographs and attachment limits on email and ticketing systems that cap files around 40KB.
Reaching 40KB means discarding roughly 102x the data in a typical 4MB phone photograph, and nothing restores it. Repeated compression still accumulates damage, so work from the original rather than a file that has already been through this once.
The image is decoded and re-encoded by your own browser using the Canvas API. There is no upload endpoint, so the file cannot reach a server; closing the tab discards everything.
