What Does Image Quality Mean in JPG or WebP Compression?
Quality is a control that changes the trade-off between visual fidelity and encoded file size. A higher setting generally keeps more detail and creates a larger file.
What to do
Do not treat a quality percentage as a universal standard. Compare the actual output at its intended viewing size. The simplest next step is to Compress Image. If the issue is actually about jpg to webp, see JPG to WebP as well.
Why this happens
Image problems often come from three separate variables: pixel dimensions, encoded file size and file format. Changing one does not automatically solve the others. A very large photo may need resizing even when its format is already JPG; a transparent graphic may need PNG or WebP even when the file size is acceptable; and an upload limit may be measured in megabytes rather than pixels.
Before editing, check the requirements of the place where the image will be used. That gives you a concrete target and reduces unnecessary quality loss. When possible, keep the original file and create a delivery copy for the specific destination.
Common questions
Is 100% quality always best?
Not necessarily. The extra file weight may be invisible at normal display sizes.
Why can 80% look different on two images?
The same numeric setting interacts with image content and the encoder, so visual results vary.
How should I choose quality?
Start moderately, inspect important edges and textures, and increase or decrease based on the actual result.