How to Compress Images Without Excessive Quality Loss
Practical quality settings for JPEG, PNG and WebP, with a test you can repeat on your own photos.
Start from the largest original you have, never from an already-compressed copy. Each re-save discards more detail.
For photographs, JPEG quality 80–85 or WebP quality 80 usually looks almost identical to the original while cutting the file roughly in half. Drop below 70 only when file size matters more than fine detail.
For graphics, logos and screenshots, PNG keeps edges sharp, but the file can be large. Try WebP at quality 90 first — it often beats PNG on size without visible loss.
Always compare at 100% zoom, not in a small thumbnail. Banding in skies and soft text are the first signs you went too far.
Measure, do not guess: the UMARIX Image Compressor shows the real output size and percentage saved for every file, so you can test quality 90, 80 and 70 on the same image and pick the smallest file you cannot tell apart from the original.