React Doctor
makeplane/plane
Scans React code for lint, accessibility, bundle size and architecture issues, reports a health score and checks that changes do not lower it.
A skill your agent uses when reviewing image assets, markup, and CDN or build transforms related to Lazy load offscreen images.
Install Offscreen Lazy
$ npx skills add thedaviddias/Front-End-Checklist --skill offscreen-lazy -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offscreen-lazy --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/offscreen-lazy .claude/skills/offscreen-lazy && 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 "offscreen-lazy" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offscreen-lazy into .claude/skills/offscreen-lazy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offscreen-lazy", 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/offscreen-lazyType 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 offscreen-lazy -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offscreen-lazy --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/offscreen-lazy .agents/skills/offscreen-lazy && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "offscreen-lazy" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offscreen-lazy into .agents/skills/offscreen-lazy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offscreen-lazy", 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 offscreen-lazy -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offscreen-lazy --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/offscreen-lazy .cursor/skills/offscreen-lazy && 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 "offscreen-lazy" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offscreen-lazy into .cursor/skills/offscreen-lazy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offscreen-lazy", 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/offscreen-lazy--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 offscreen-lazy -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offscreen-lazy --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/offscreen-lazy .gemini/skills/offscreen-lazy && 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 "offscreen-lazy" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offscreen-lazy into .gemini/skills/offscreen-lazy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offscreen-lazy", 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 offscreen-lazyInstalls 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 offscreen-lazy -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/offscreen-lazy .github/skills/offscreen-lazy && 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 "offscreen-lazy" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offscreen-lazy into .github/skills/offscreen-lazy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offscreen-lazy", 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 offscreen-lazy -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 offscreen-lazy --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/offscreen-lazy .opencode/skills/offscreen-lazy && 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 "offscreen-lazy" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offscreen-lazy into .opencode/skills/offscreen-lazy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offscreen-lazy", 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
offscreen-lazy- GitHub stars
- 74k
- Token cost
- ~842 tokens
- SKILL.md length
- 405 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 Lazy load offscreen images.
- 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 Lazy load offscreen images
What it does
Offscreen Lazy is an agent skill from thedaviddias/Front-End-Checklist. Use when reviewing image assets, markup, and CDN or build transforms related to Lazy load offscreen images. Check encoded size, rendered size, loading strategy, and above-the-fold impact together. Missing loading='lazy' is only a valid finding when you can reasonably tell the image is offscreen or non-critical.
Its SKILL.md is about 840 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`).
It sits in Frontend & Design, covering Web performance. 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 Lazy load offscreen images
Example prompts
- “/offscreen-lazy”
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
Offscreen Lazy loads about 842 tokens when it runs, and up to ~2.4k if it reads all its reference files. Until then it costs about 82 tokens; SKILL.md has 405 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). 405 words, ~842 tokens.
Download SKILL.mdSave it as
.claude/skills/offscreen-lazy/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- offscreen-lazy
- description
- Use when reviewing image assets, markup, and CDN or build transforms related to Lazy load offscreen images. Check encoded size, rendered size, loading strategy, and above-the-fold impact together. Missing `loading='lazy'` is only a valid finding when you can reasonably tell the image is offscreen or non-critical.
- metadata.category
- images
- metadata.priority
- high
- metadata.difficulty
- beginner
- metadata.estimatedTime
- 10
- metadata.source
- frontendchecklist.io
- metadata.url
- https://frontendchecklist.io/rules/images/offscreen-lazy
Lazy load offscreen images
Lazy loading eliminates unnecessary image downloads on initial page load. A page with 20 images below the fold may transfer several megabytes of data that users who don't scroll will never see. Deferring these downloads reduces Time to Interactive, improves LCP for above-fold content, and saves bandwidth—particularly impactful for users on metered mobile connections.
Quick Reference
- Add
loading="lazy"to all<img>elements below the fold - Never lazy-load the LCP image (hero, first product image)—use
fetchpriority="high"instead - Always pair
loading="lazy"withwidthandheightattributes to prevent CLS - Native
loading="lazy"has universal support in all modern browsers—no JavaScript polyfill needed - If fold position is unclear from the snippet, do not invent a lazy-loading defect
Check
Scan all <img> elements in this codebase. Identify: 1) Any <img> elements below the fold (not in the first viewport) that are missing loading="lazy". 2) Any <img> elements marked loading="lazy" that appear to be above the fold (hero images, first product images, logos in headers). 3) Any <img> with loading="eager" below the fold. Report the above-fold images that should NOT have lazy loading separately from below-fold images that should have it. If fold position cannot be inferred from the snippet, do not report missing lazy loading as a defect.
Fix
For images that should use lazy loading: 1) Add loading="lazy" to all <img> elements that appear below the fold. 2) Remove loading="lazy" from any hero, logo, or first-visible image—these should load immediately. 3) Ensure all lazy-loaded images have explicit width and height attributes to prevent CLS. 4) For the LCP image specifically, add fetchpriority="high" and remove loading="lazy". Show the corrected HTML for each modified image.
Show full SKILL.md (132 more words)Show less
Explain
Explain how native browser lazy loading works. The loading="lazy" attribute tells the browser to defer image download until the image is within a browser-defined distance from the viewport (typically 1250px on a slow connection). This reduces the data transferred on initial load, lowers Time to Interactive, and saves bandwidth for users who never scroll to those images. Browser support is universal in modern browsers. The critical caveat: never lazy-load the LCP image—it must load as fast as possible.
Code Review
Review image assets, markup, and delivery configuration related to Lazy load offscreen images. 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/offscreen-lazy
© 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/offscreen-lazy of thedaviddias/Front-End-Checklist.
- SKILL.md
- references/rule.md
Open the folder on GitHubat commit e8d14d0
Compare with similar skills
Offscreen Lazy 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 |
|---|---|---|---|---|---|---|
| Offscreen Lazy this skillthedaviddias/Front-End-Checklist | 74k | — | ~842 | Automated safety check: Pass | MIT | |
| React Doctormakeplane/plane | 61k | 12 repos | ~657 | Automated safety check: Pass | AGPL-3.0 | |
| Fixing Motion Performanceibelick/ui-skills | 9.5k | 5 repos | ~1.4k | Automated safety check: Pass | MIT | |
| GSAP Performance Tuninggreensock/gsap-skills | 16k | 4 repos | ~1k | Automated safety check: Pass | MIT | |
| React Frontend Development Guidelinesdiet103/claude-code-infrastructure-showcase | 10k | 2 repos | ~2.9k | Automated safety check: Pass | MIT | |
| Web Quality Auditaddyosmani/web-quality-skills | 2.9k | — | ~2.6k | Automated safety check: Pass | MIT |
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Guides the agent to keep GSAP animations smooth by animating transforms and opacity, batching DOM reads and writes, and avoiding layout-heavy properties.
React Frontend Development Guidelines
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Guidelines for React 18 and TypeScript apps covering Suspense data fetching, lazy loading, feature folders, MUI v7 styling, TanStack Router and performance.
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Google SEO APIs: Search Console (Search Analytics, URL Inspection, Sitemaps), PageSpeed Insights v5, CrUX field data with 25-week history, Indexing API v3, and GA4 organic traffic.
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Related
Categories
Questions about Offscreen Lazy
What does Offscreen Lazy do?
A skill your agent uses when reviewing image assets, markup, and CDN or build transforms related to Lazy load offscreen images. Offscreen Lazy is an agent skill from thedaviddias/Front-End-Checklist. Use when reviewing image assets, markup, and CDN or build transforms related to Lazy load offscreen images.
When should I use Offscreen Lazy?
Offscreen Lazy fits situations like: reviewing image assets; build transforms related to Lazy load offscreen images.
How do I install Offscreen Lazy in Claude Code?
Run `npx skills add thedaviddias/Front-End-Checklist --skill offscreen-lazy -a claude-code`. Or copy the skill folder (skills/offscreen-lazy in thedaviddias/Front-End-Checklist) into .claude/skills/offscreen-lazy in your project. Claude Code loads it when a task matches its description.
How do I install Offscreen Lazy in Codex?
Run `npx skills add thedaviddias/Front-End-Checklist --skill offscreen-lazy -a codex`. Or copy the skill folder (skills/offscreen-lazy in thedaviddias/Front-End-Checklist) into .agents/skills/offscreen-lazy in your project. Codex loads it when a task matches its description.
Can I use Offscreen Lazy 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 offscreen-lazy -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/offscreen-lazy, .gemini/skills/offscreen-lazy, .github/skills/offscreen-lazy and .opencode/skills/offscreen-lazy in your project.
What does Offscreen Lazy need to run?
SKILL.md names no scripts, command-line tools or credentials: Offscreen Lazy is instructions for the agent only.
Does Offscreen Lazy 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 Offscreen Lazy 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 Offscreen Lazy use?
Offscreen Lazy 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 Offscreen Lazy use?
About 842 tokens (SKILL.md is roughly 3.4k 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 1.6k tokens, read only when the agent opens those files.
What are the alternatives to Offscreen Lazy?
Skills that share tags, products or a category with Offscreen Lazy: React Doctor (makeplane/plane, 61k stars), Fixing Motion Performance (ibelick/ui-skills, 9.5k stars), GSAP Performance Tuning (greensock/gsap-skills, 16k stars) and React Frontend Development Guidelines (diet103/claude-code-infrastructure-showcase, 10k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Offscreen Lazy?
thedaviddias (a GitHub user) maintains it in thedaviddias/Front-End-Checklist, which has 74,412 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.