Compression depends on the output format
Re-encoding an already optimized JPG at high quality can increase its file size. Converting a photo to PNG, BMP, or uncompressed TIFF can also create a much larger file even with fewer pixels. There is no universal quality setting or percentage reduction that works for every image.
Compare the same source under controlled settings
Keep the original and export separate JPG or WebP copies at different quality settings. Compare downloaded bytes and inspect text, edges, and gradients at the same display scale. If the image is still too large, reduce pixel dimensions before testing again. Do not repeatedly compress the previous lossy export.
Handle transparency and browser differences
JPG does not preserve transparency; choose a background before export. PNG can suit transparent graphics and sharp edges, while lossy formats may suit photographs. In this toolbox the quality slider does not make PNG lossy. Export sizes vary with content and browser encoders, so use the actual download size rather than a promised saving.
Current capabilities and limits
A target of 50 KB means at most 51,200 bytes. The compressor lowers JPG, WebP or available AVIF quality without resizing. It reports when the target cannot be reached; PNG and other formats ignore the target.
The target is an upper limit, not an exact file size. The tool searches a limited set of quality settings and shows the actual byte size; some images cannot meet the target without resizing.