Reviewed practical guide
How to compress an image without degrading it unnecessarily
Adjust quality against a measurable target and inspect detail, colour and transparency before publishing the result.
Compress image re-encodes the file at the selected quality. It keeps a common source format—JPG, PNG, WebP or AVIF—and applies settings appropriate to that codec. PNG reduction may use a palette, so photographs and gradients deserve particular inspection.
Perceived quality depends more on the subject than on a single number. Photographs can tolerate loss that becomes obvious in small text, icons, screenshots and high-contrast edges. The useful target is the smallest file that remains correct for its destination.
What result to expect
You will receive a re-encoded image whose filename includes “compress-image”; the source remains separate.