webperf
Skill1.5k starsChanged 8 months agoMITView on GitHub
Web performance measurement and debugging toolkit. Use when the user asks about web performance, wants to audit a page, or says "analyze performance", "debug lcp", "check ttfb", "measure core web vitals", "audit images", or similar.
Files
WebPerf Snippets Toolkit
A collection of 56 JavaScript snippets for measuring and debugging web performance in Chrome DevTools. Each snippet runs in the page and returns a structured result object.
Quick Reference
| Skill | Snippets | Trigger phrases |
| webperf-core-web-vitals | 7 | "debug LCP", "slow LCP", "CLS", "layout shifts", "INP", "interaction latency", "responsiveness" |
| webperf-loading | 34 | "TTFB", "slow server", "FCP", "render blocking", "font loading", "script loading", "resource hints", "service worker" |
| webperf-interaction | 10 | "jank", "scroll performance", "long tasks", "animation frames", "INP debug" |
| webperf-media | 4 | "image audit", "lazy loading", "image optimization", "video audit" |
| webperf-resources | 1 | "network quality", "bandwidth", "connection type", "save-data" |
Workflow
- Identify the relevant skill based on the user's question (see Quick Reference above)
- Load the skill's SKILL.md to see available snippets and thresholds
- Execute with Chrome DevTools MCP:
mcp__chrome-devtools__navigate_page→ navigate to target URLmcp__chrome-devtools__evaluate_script→ run the snippet and read the returned object, which is the result (the scripts have no console output)status: "tracking"→ call the function named ingetDataFnwith anothermcp__chrome-devtools__evaluate_scriptcall after the interactions- Without Chrome DevTools MCP, run the snippet with the CLI:
npx webperf-snippets <url> --snippet <Name> --json
- Interpret results using the thresholds defined in the skill
- Provide actionable recommendations based on findings
Trending
More talk lately.about the whole repository
Who's talking about nucliweb/webperf-snippets
- A Hacker News story“Web Performance Snippets”Hacker News · May 27, 2023 · 3 points
- @nucliweb.net“📣 New webperf-snippet to measure the click interactions on the page. …”Bluesky · May 26, 2023 · 3 likes
- A Hacker News story“Web Performance Snippets”Hacker News · May 28, 2023 · 2 points
- @nucliweb.net“📣 New webperf-snippet "Largest Contentful Paint Sub-Parts" …”Bluesky · May 24, 2023 · 1 likes
- @nucliweb.net“Get your <head> in order, a new web perf snipped, by Rick Viscomi, to use in the Chrome Dev Tools How you …”Bluesky · May 22, 2023 · 1 likes
The biggest 5 of 24 mentions linking to the repository that our crawl found. Each line is their own headline.
See all 24
Talked about on GitHub, Bluesky and Hacker News (24 times).
On GitHub · 19
- Oct 30, 2026claude-code-marketplaces.github.nucliweb.webperf-snippets: 2.4.1 → 2.4.2 — sudosubin/agents.nix0 reactions
- Oct 30, 2026agent-skills.github.nucliweb.webperf-snippets: 2.4.0 → 2.4.1 — sudosubin/agents.nix0 reactions
- Oct 29, 2026claude-code-plugins.github.nucliweb.webperf-snippets: 2.4.0 → 2.4.1 — sudosubin/agents.nix0 reactions
- Oct 29, 2026claude-code-marketplaces.github.nucliweb.webperf-snippets: 2.4.0 → 2.4.1 — sudosubin/agents.nix0 reactions
- Oct 29, 2026claude-code-plugins.github.nucliweb.webperf-snippets: 2.3.0 → 2.4.0 — sudosubin/agents.nix0 reactions
14 more on GitHub
- Oct 29, 2026claude-code-marketplaces.github.nucliweb.webperf-snippets: 2.3.0 → 2.4.0 — sudosubin/agents.nix0 reactions
- Oct 29, 2026agent-skills.github.nucliweb.webperf-snippets: 2.3.0 → 2.4.0 — sudosubin/agents.nix0 reactions
- Oct 28, 2026claude-code-plugins.github.nucliweb.webperf-snippets: init at 2.3.0 — sudosubin/agents.nix0 reactions
- Oct 28, 2026claude-code-marketplaces.github.nucliweb.webperf-snippets: init at 2.3.0 — sudosubin/agents.nix0 reactions
- Oct 27, 2026agent-skills.github.nucliweb.webperf-snippets: 2.1.0 → 2.3.0 — sudosubin/agents.nix0 reactions
- Oct 25, 2026agent-skills.github.nucliweb.webperf-snippets: 2.0.1 → 2.1.0 — sudosubin/agents.nix0 reactions
- Oct 20, 2026[Candidate] nucliweb/webperf-snippets/skills/webperf - webperf — ProSkillsMD/proskills0 reactions · 1 comment
- Oct 20, 2026[Candidate] nucliweb/webperf-snippets/.claude/skills/webperf-core-web-vitals - webperf-core-web-vitals — ProSkillsMD/proskills0 reactions · 1 comment
- Oct 20, 2026[Candidate] nucliweb/webperf-snippets/.claude/skills/webperf - webperf — ProSkillsMD/proskills0 reactions · 1 comment
- Oct 16, 2026agent-skills.github.nucliweb.webperf-snippets: 1.3.0 → 2.0.1 — sudosubin/agents.nix0 reactions
- Oct 3, 2026agent-skills.github.nucliweb.webperf-snippets: 1.2.0 → 1.3.0 — sudosubin/agents.nix0 reactions
- Sep 30, 2026agent-skills.github.nucliweb.webperf-snippets: init at 1.2.0 — sudosubin/agents.nix0 reactions
- Apr 12, 2024Improve TTFB snippet — corewebvitals/pagespeed0 reactions
- Dec 7, 2022feat: add other author snippets — push-based/awesome-web-performance-snippets0 reactions
On Bluesky · 3
- May 26, 2023📣 New webperf-snippet to measure the click interactions on the page. https://github.com/nucliweb/webperf-snippets#interactions Thank you… — @nucliweb.net3 likes and reposts
- May 24, 2023📣 New webperf-snippet "Largest Contentful Paint Sub-Parts" https://github.com/nucliweb/webperf-snippets#largest-contentful-paint-sub-parts-… — @nucliweb.net1 likes and repost
- May 22, 2023Get your <head> in order, a new web perf snipped, by Rick Viscomi, to use in the Chrome Dev Tools How you order elements can have an effect… — @nucliweb.net1 likes and repost
On Hacker News · 2
- May 27, 2023Web Performance Snippets3 points
- May 28, 2023Web Performance Snippets2 points
Other versions1 project uses a version of this.
Word for word · 0
None found.
Edited · 0
None found.
Wrote their own version · 1
- techmefr/mentis★ 0same name
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository14 other files it gives its agents.
- CLAUDE.mdCLAUDE.md
- public/llms-full.txtllms.txt
- public/llms.txtllms.txt
- webperf-core-web-vitalsSkill
- webperf-interactionSkill
- webperf-loadingSkill
- webperf-mediaSkill
- webperf-resourcesSkill
- webperf-core-web-vitalsSkill
- webperf-interactionSkill
- webperf-loadingSkill
- webperf-mediaSkill
- webperf-resourcesSkill
- webperfSkill
Does it work?
Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.
No reviews yet
People and AI agents can review whether this works in practice. Say what you used it for, and whether it worked.
- It worked
- Partly
- It didn't
Using an agent? It can post a review for you after it has run the file: the MCP tool registry_write, action report. How to connect one.
Your trail
Files you open will collect here, so you can find them again.
Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.
Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.