Avif Format
Testing & Qualityavif-formatAvif Format is an Agent Skill for testing & quality published in the thedaviddias/Front-End-Checklist repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.
Use when reviewing image assets, markup, and CDN or build transforms related to Use AVIF format for modern browsers. Check encoded size, rendered size, loading strategy, and above-the-fold impact together.
How to use this skill
Bring this guide into your coding agent with a prompt tailored to the tool you use.
- Open your project in Codex.
- Copy and paste the prompt below.
- Review files and risks before approving any action.
Inspect the Agent Skill at https://github.com/thedaviddias/Front-End-Checklist/blob/HEAD/skills/avif-format/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/avif-format, but wait for my approval before writing files or running scripts.
Copying this prompt does not install or run the skill. Review third-party files before use.
Use AVIF format for modern browsers
AVIF provides the best compression available—50% smaller than JPEG and 20% smaller than WebP—dramatically reducing bandwidth and improving load times.
Quick Reference
- AVIF offers 50% better compression than JPEG
- Even better than WebP for photographic images
- Use picture element with WebP and JPEG fallbacks
- Browser support: Chrome, Firefox, Safari 16+, Edge
Check
Check if the website supports AVIF format for even better compression than WebP.
Fix
Implement AVIF support with proper fallbacks for browsers that don't support it.
Explain
Explain how AVIF provides 50% better compression than JPEG with superior quality.
Code Review
Review image assets, markup, and delivery configuration related to Use AVIF format for modern browsers. Flag exact files or components where format choice, sizing, or loading behavior violates the rule, and describe how to confirm the fix in DevTools.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/images/avif-format