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webfont-format

Testing & Quality
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Use when reviewing stylesheets, component styles, and responsive behavior related to Optimize web font formats. Check the rendered layout across breakpoints and interaction states before proposing a fix.

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How to use this skill

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  1. Open your project in Codex.
  2. Copy the prompt below and paste it into your agent.
  3. Review the proposed files and risks before you approve installation.
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I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/thedaviddias/Front-End-Checklist/blob/HEAD/skills/webfont-format/SKILL.md

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First, summarize what it does, its dependencies, license status if identifiable, and any risks. Show the exact files you propose to add under .agents/skills/webfont-format/. Do not write files or run scripts until I approve.

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Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

Optimize web font formats

Modern font formats reduce file sizes by 30-50%—directly improving page load speed and Core Web Vitals scores.

Quick Reference

  • Use WOFF2 as primary format (~30% smaller than WOFF)
  • Include WOFF fallback for older browsers
  • Apply font-display: swap for better perceived performance
  • Preload critical fonts and subset to reduce file sizes

Check

Verify that web fonts use modern formats (WOFF2, WOFF) with proper fallbacks and are optimized for performance with font-display and preloading strategies.

Fix

Convert fonts to WOFF2/WOFF formats, implement proper font loading strategies, and optimize font delivery with compression and caching.

Explain

Explain how modern web font formats reduce file sizes, improve loading performance, and provide better browser support compared to legacy formats.

Code Review

Review stylesheets, component styles, and responsive states related to Optimize web font formats. Flag exact selectors, declarations, or breakpoints that violate the rule in the rendered UI.

For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/en/rules/css/webfont-format