URLs are the risk
HTML pages keep their URLs. Images often change extension. Any inbound image link (newsletters, PDFs, partners) needs a redirect or a same-path replace.
Why it matters
- Google Images URLs can 404.
- Email archives point at old JPEGs.
- CDNs cache the old object.
How to do it
- Inventory top templates. Convert those images first.
- Prefer replacing the file in the CMS so the HTML URL updates in one place.
- If the public URL must stay
photo.jpg, some servers can still serve WebP via content negotiation — that is harder. Simpler: new.webp+ 301. - Purge CDN. Submit updated sitemaps.
Settings that work
Same visual settings as a normal convert. Migration is about process, not a special quality number.