Images usually account for most of a page’s weight. Making them lighter has an immediate effect.

Compress

Compression reduces a file’s weight with a quality loss the eye cannot see. Dedicated plugins do it automatically on every upload.

Choose the format

• WebP: a modern format, far lighter than JPEG/PNG at equal quality — the one to prefer.
• JPEG: for photographs.
• PNG: for images with a transparent background (logos).

Key takeaway: compressing and serving WebP can cut image weight by 50% or more.