Exact limits.
Choose the number from the upload form. UnderPix verifies the actual output bytes before you download.
File-size control for real upload limits
Make every
upload fit.
Compress a photo to 200 KB, 500 KB, or any limit your form asks for. The file never leaves this browser.
Start compressing01 / Compressor
Tell us the limit.
We find the fit.
IMAGE COMPRESSOR
No upload
KB maximum
PreviewWaiting for an image
+Your image will appear hereChoose a target, then drop a file
Original--
UnderPix output--
Ready to upload
A size check does not verify the destination’s format, dimensions, or photo rules.
Very large images may be scaled down. Please check text and faces in the preview.
Processed images
02 / Why UnderPix
A smaller file.
A clearer next step.
Private by default.
Compression runs inside your browser. Your photo, filename, and pixels stay on your device.
Quality first.
The algorithm searches for the highest quality that fits, then reduces dimensions only when it has to.
03 / Good to know
Ready when
you are.
Will my image be uploaded?
No. UnderPix uses the browser Canvas API and Blob encoder. The selected file is processed in memory and never sent to a server.
Does 200 KB mean exactly 200 KB?
It means at most 200 KB. UnderPix selects the largest output that passes the limit, leaving a small margin for portals that count bytes differently.
What if the image cannot reach the target?
The result is marked as the closest available output. Try JPG or WebP, or choose a larger limit to keep more detail.