Start with the destination
A website avatar, document attachment, and printed photo need different outputs. Find any required pixel dimensions, accepted formats, and file limit first. If only a byte limit is specified, do not immediately discard pixels that may still be useful.
Keep the original. The browser tool creates a separate download, so you can compare alternatives without replacing your source. It handles the selected image; it does not compress an entire phone library or recover storage by deleting photos.
Use a small comparison rather than a guess
The following procedure separates resizing from encoding, helping you see which change affects the result.
- Select a still image and note its original dimensions and file size.
- Export once using the same dimensions and an appropriate output format. Inspect fine text, edges, and gradients.
- Make another export with a smaller width while keeping the aspect ratio.
- Compare both at the intended display size, not only when enlarged to fill a large screen.
- Download the version that meets the destination’s requirement while retaining the detail you need.
Understand the quality control
In browser image export, a quality setting applies to formats that support lossy encoding; it is not a universal percentage of retained detail. Lowering it does not promise a particular saving, and PNG uses a different workflow.
An already optimized image may grow after re-encoding. Compare the actual bytes, and keep the source when no useful improvement occurs. For a comparison of transparency and format choices, read the JPEG, PNG, and WebP guide next.