Image compression tools
Shrink files with a quality slider and an honest size readout.
Compression is a trade-off between file size and fidelity, and the only useful interface is one that shows you both sides. KaiConvert reports the original size, the encoded size and the percentage saved — measured from the actual output, not estimated from a formula.
The largest saving usually comes before compression, though. If your image is bigger than it will ever be displayed, resize it first: that removes pixels entirely rather than storing them more cheaply.