Compress a JPG to 100 KB
Photo upload forms ask for 100 KB more often than any other number. Getting there by dragging a quality slider is guesswork; giving the encoder a target is not.
Compress Image — free and local
Shrinks JPG, PNG and WebP to a target size or dimension, in the browser.
What 100 KB means for a photo
A 12 MP phone photo is 3–6 MB. At 100 KB it must also lose dimensions: compression alone cannot bridge a 40× gap without visible blocking. A 100 KB image is roughly 800–1000 px on the long edge at moderate quality — sharp on a phone screen, soft when printed.
That is fine for the usual purpose. ID photos, avatar uploads and form attachments are displayed small; nobody inspects them at 100%.
Why the tool may downscale before it lowers quality
Quality is the cheaper lever only up to a point. Below about 40% JPEG quality, artefacts become obvious rings around edges; halving the dimensions instead often looks better at the same file size.
The encoder searches quality first, then applies a modest downscale only if quality alone cannot reach the target — and it reports the dimensions it settled on.
A privacy side effect worth knowing
Re-encoding through canvas drops EXIF, including GPS coordinates, camera model and timestamps. Phone photos posted publicly routinely leak their location this way; a compressed copy does not.
Questions
Can it hit exactly 100 KB?
It aims under the target. If the result lands slightly below — 94 KB, say — that is the binary search stopping at the highest quality that fits.
Will the photo look bad?
At 100 KB on a phone screen, usually indistinguishable. Printed at A4, visibly soft. That is the trade the form is asking you to make.
Does it work on PNG and WebP?
Yes, and converting a photographic PNG to JPEG is often the biggest single saving available.
Related
SlimPDF runs every tool in your browser. No file is ever uploaded, stored or shared.