1. Resize to the size shown
Use Resize image to match the width the page actually displays.
2. Compress
Compress image reduces file size; compare before and after.
3. Consider WebP
JPG to WebP often makes smaller files that modern browsers display.
Good to know
Resize first, then compress: shrinking the pixel dimensions usually saves far more than the quality setting alone.
Questions
Can I do many images at once?
Yes. Resize and Compress image both take batches.
Related: Convert iPhone photos (HEIC) to JPG · Resize many images at once