Compress JPEG

JPEG has been the default format for photographs since the early 1990s, and for good reason: its encoder discards information in a way that mirrors how human vision works. It stores brightness in more detail than color and drops high-frequency texture the eye can’t resolve, which lets a typical photo shrink dramatically before any difference becomes visible. The quality setting simply controls how aggressive that process is.

For most photos, a quality level between 75 and 85 is the sweet spot — files shrink to a fraction of the camera original while remaining indistinguishable at normal viewing size. Going above 90 grows the file quickly with almost no visual gain; going below 60 starts to show blockiness in smooth gradients like skies and skin. This tool defaults to a balanced level, and you can override it or set an exact target size in kilobytes under Options.

Because compression runs in your browser, photos are never uploaded anywhere. Re-encoding also strips embedded camera metadata such as EXIF tags, which saves a little extra space and removes details like the GPS coordinates of where a photo was taken — worth knowing before you share images publicly. If you need that metadata, keep the untouched original and share the compressed copy.

One caution: JPEG loss is cumulative. Each time a photo is opened and re-saved as JPEG, a little more detail is gone for good. Always compress from your best available original rather than an already-compressed copy, and keep that original — this tool never touches your source files, so every download is a separate copy.