Image optimization is usually the fastest performance win on content-heavy pages. The goal is not maximum compression everywhere. The goal is predictable quality at the smallest practical size.
Core checklist
1. Choose format by asset type
- Photos: JPG or WebP (AVIF when supported).
- Logos/UI assets: PNG or WebP with transparency.
- Hero images: WebP/AVIF plus fallback strategy.
2. Export to display size, not source size
If the image renders at 1200px wide, do not ship a 4000px file.
3. Provide responsive variants
Serve smaller files to smaller viewports to avoid wasting bandwidth.
4. Compress with review
Use a quality setting that keeps faces, text, and edges clean. Check final output at real page size.
5. Keep naming and alt text meaningful
Human-readable names and useful alt text help both usability and maintenance.
Performance guardrails for teams
- Set max file size targets per component (card image, hero, thumbnail).
- Reject oversized uploads in editorial workflow.
- Keep original source files outside production delivery paths.
- Re-check pages after theme/design updates that change image dimensions.
Common mistakes
- Shipping PNG for large photographs.
- Using one export preset for every image type.
- Forgetting mobile viewport weight.
- Replacing crisp SVG/PNG UI assets with over-compressed JPG.
QA pass before publish
- Open the page on mobile data throttling.
- Check visual quality on key breakpoints.
- Compare total page weight before and after changes.
- Confirm no layout shift from late-loading dimensions.
Bottom line
Good image optimization is a workflow, not a one-time tool run. Format choice, target dimensions, and repeatable QA are what keep pages fast and still looking professional.