'Compress to under 100 KB' is a common requirement — passport photo uploads, some visa forms, older CMS platforms, marketplace image caps. This tool iterates on quality settings until it hits your target file size while keeping quality as high as possible. It runs binary search on the JPEG quality slider, encoding at each step, until the smallest quality-drop that fits is found.
How it works
Binary search on the quality parameter. Encode at quality 50, check size; if too big, try 30; if too small, try 70; converge. Usually finds an optimal setting in 5–7 iterations. The final quality is displayed so you know how much compression was applied.
Handling impossible targets
If even quality 1 doesn't fit your target, the tool warns and suggests resizing the image first. Below quality 30, output looks bad enough that most humans prefer a smaller, sharper image over a full-size blurry one — the tool offers to auto-resize when quality would need to drop below that threshold.
Format choice matters
WebP hits smaller targets than JPEG at the same visual quality. If your platform accepts WebP, use it — you'll get better output for the same size cap. If it doesn't (many older upload forms don't), JPEG is the pragmatic choice.