Schema Markup
alirezarezvani/claude-skills
When the user wants to implement, audit, or validate structured data (schema markup) on their website.
A skill your agent uses when reviewing image assets, markup, and CDN or build transforms related to Use AVIF format for modern browsers.
MITAuto-check passed
Install Avif Format
$ npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install thedaviddias/Front-End-Checklist avif-format --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/avif-format .claude/skills/avif-format && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "avif-format" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/avif-format into .claude/skills/avif-format/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "avif-format", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/avif-formatType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install thedaviddias/Front-End-Checklist avif-format --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/avif-format .agents/skills/avif-format && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "avif-format" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/avif-format into .agents/skills/avif-format/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "avif-format", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install thedaviddias/Front-End-Checklist avif-format --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/avif-format .cursor/skills/avif-format && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "avif-format" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/avif-format into .cursor/skills/avif-format/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "avif-format", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/thedaviddias/Front-End-Checklist.git --path skills/avif-format--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install thedaviddias/Front-End-Checklist avif-format --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/avif-format .gemini/skills/avif-format && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "avif-format" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/avif-format into .gemini/skills/avif-format/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "avif-format", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install thedaviddias/Front-End-Checklist avif-formatInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/avif-format .github/skills/avif-format && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "avif-format" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/avif-format into .github/skills/avif-format/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "avif-format", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install thedaviddias/Front-End-Checklist avif-format --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/avif-format .opencode/skills/avif-format && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "avif-format" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/avif-format into .opencode/skills/avif-format/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "avif-format", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
avif-format- GitHub stars
- 74k
- Token cost
- ~393 tokens
- SKILL.md length
- 152 words
- Files
- 2 (incl. references)
- Skills in repo
- 390
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when reviewing image assets, markup, and CDN or build transforms related to Use AVIF format for modern browsers.
- Reviewing image assets
- SKILL.md covers Quick Reference, Check, Fix and Explain, plus 1 more section
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- Build transforms related to Use AVIF format for modern browsers
What it does
Avif Format is an agent skill from thedaviddias/Front-End-Checklist. 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.
Its SKILL.md is about 390 tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/rule.md`).
The repository describes itself as: 🗂 The essential checklist for modern web development, for humans and AI agents. The licence is MIT.
When your agent uses it
- Reviewing image assets
- Build transforms related to Use AVIF format for modern browsers
Example prompts
- “/avif-format”
What it can do on your machine
Read from SKILL.md and the folder at commit e8d14d0. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
frontendchecklist.io
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Avif Format loads about 393 tokens when it runs, and up to ~1.7k if it reads all its reference files. Until then it costs about 54 tokens; SKILL.md has 152 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from thedaviddias/Front-End-Checklist at commit e8d14d0, republished under its MIT licence (© thedaviddias). 152 words, ~393 tokens.
Download SKILL.mdSave it as
.claude/skills/avif-format/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- avif-format
- description
- 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.
- metadata.category
- images
- metadata.priority
- medium
- metadata.difficulty
- intermediate
- metadata.estimatedTime
- 20
- metadata.source
- frontendchecklist.io
- metadata.url
- https://frontendchecklist.io/rules/images/avif-format
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/rules/images/avif-format
© thedaviddias, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 1 other file (references) in skills/avif-format of thedaviddias/Front-End-Checklist.
- SKILL.md
- references/rule.md
Open the folder on GitHubat commit e8d14d0
Compare with similar skills
Avif Format next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Avif Format this skillthedaviddias/Front-End-Checklist | 74k | — | ~393 | Automated safety check: Pass | MIT | |
| Schema Markupalirezarezvani/claude-skills | 28k | 1 repos | ~2.9k | Automated safety check: Pass | MIT | |
| Schema Markup Generatorsickn33/agentic-awesome-skills | 47k | 1 repos | ~2.1k | Automated safety check: Pass | MIT | |
| Remotion Markupremotion-dev/remotion | 63k | 2 repos | ~4.6k | Automated safety check: Pass | Custom licence | |
| Cdn Setupsickn33/agentic-awesome-skills | 47k | 2 repos | ~2.9k | Automated safety check: Pass | MIT | |
| Schema Markupmohitagw15856/pm-claude-skills | 1.4k | — | ~838 | Automated safety check: Pass | MIT |
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Schema Markup Generator
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Cdn Setup
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Configure CDNs for content delivery. An agent skill from sickn33/agentic-awesome-skills.
Schema Markup
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Questions about Avif Format
What does Avif Format do?
A skill your agent uses when reviewing image assets, markup, and CDN or build transforms related to Use AVIF format for modern browsers. Avif Format is an agent skill from thedaviddias/Front-End-Checklist. Use when reviewing image assets, markup, and CDN or build transforms related to Use AVIF format for modern browsers.
When should I use Avif Format?
Avif Format fits situations like: reviewing image assets; build transforms related to Use AVIF format for modern browsers.
How do I install Avif Format in Claude Code?
Run `npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a claude-code`. Or copy the skill folder (skills/avif-format in thedaviddias/Front-End-Checklist) into .claude/skills/avif-format in your project. Claude Code loads it when a task matches its description.
How do I install Avif Format in Codex?
Run `npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a codex`. Or copy the skill folder (skills/avif-format in thedaviddias/Front-End-Checklist) into .agents/skills/avif-format in your project. Codex loads it when a task matches its description.
Can I use Avif Format in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add thedaviddias/Front-End-Checklist --skill avif-format -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/avif-format, .gemini/skills/avif-format, .github/skills/avif-format and .opencode/skills/avif-format in your project.
What does Avif Format need to run?
SKILL.md names no scripts, command-line tools or credentials: Avif Format is instructions for the agent only.
Does Avif Format access the network?
SKILL.md names 1 domain. As links in the text: frontendchecklist.io. This is read from the text; nothing was executed.
Is Avif Format safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Avif Format use?
Avif Format is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Avif Format use?
About 393 tokens (SKILL.md is roughly 1.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.3k tokens, read only when the agent opens those files.
What are the alternatives to Avif Format?
Skills that share tags, products or a category with Avif Format: Schema Markup (alirezarezvani/claude-skills, 28k stars), Schema Markup Generator (sickn33/agentic-awesome-skills, 47k stars), Remotion Markup (remotion-dev/remotion, 63k stars) and Cdn Setup (sickn33/agentic-awesome-skills, 47k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Avif Format?
thedaviddias (a GitHub user) maintains it in thedaviddias/Front-End-Checklist, which has 74,421 GitHub stars. The repository holds 390 skills in this directory. The repository was last updated on October 6, 2026.
Source: thedaviddias/Front-End-Checklist on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.