Check the requirements first
Read the destination’s format, pixel and size limits before editing. Image info reports dimensions and source bytes, but it does not inspect EXIF. Keep a separate original; enlarging a small image does not recover missing detail.
Make one controlled change at a time
Crop the composition before resizing. For a dark photo, try a small brightness adjustment and inspect highlights. For a required KB size, compare compression results and the target-met status. Visual blur and pixelation are not secure redaction.
Verify the exported copy
JPG fills transparency with white. PNG retains decoded alpha but may be larger; this WebP exporter uses a lossy quality setting. Open the downloaded copy, check edges and dimensions, and use a contact sheet when reviewing a batch.