Modern Web Guidance is a set of agent skills that supplies coding agents with curated advice on current web platform APIs, browser compatibility, performance, and accessibility. It helps agents choose newer browser capabilities instead of reproducing older web development patterns, and the catalogue entries are its installable skills and plugin.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add GoogleChrome/modern-web-guidance --skill modern-web-guidancegit clone --depth 1 https://github.com/GoogleChrome/modern-web-guidanceWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/googlechrome/modern-web-guidance/modern-web-guidance)<a href="https://agentmods.dev/skills/googlechrome/modern-web-guidance/modern-web-guidance"><img src="https://agentmods.dev/badge/skills/googlechrome/modern-web-guidance/modern-web-guidance/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/googlechrome/modern-web-guidance/modern-web-guidance"><img src="https://agentmods.dev/badge/skills/googlechrome/modern-web-guidance/modern-web-guidance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector warn
SkillSpector: 6 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium MCP Rug Pull · line 38 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 65 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 75 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 94 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 97 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 94 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00210 | $0.01864 |
| Opus 5.5 | $0.00084 | $0.00746 |
| Sonnet 5.5 | $0.00042 | $0.00373 |
| Haiku 4.5 | $0.00021 | $0.00186 |
Grade A, and why
modern-web-guidance scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
2 near-identical copies found in the catalogue:
- modern-web-guidance — 100% identical, 116 lines differ
- modern-web-guidance — 100% identical, 116 lines differ
How it starts
The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Modern Web Guidance
Search and retrieve standardized modern web best practices at the start of implementing or updating any web UI, CSS layout/animation, or client-side JS logic (dates/timezones, sanitization, performance, accessibility, UX fixes) before writing ad-hoc solutions or adding dependencies.
Usage Instructions
Step 1. Search Use Cases
Run modern-web-guidance directly with npx using a 2–5 word action-oriented query for a single web platform capability or UI pattern:
- Keep queries focused and generic: Describe the user-visible capability (
<verb> + <UI/platform object>, optionally paired with the target HTML/CSS/JS feature name if known). Omit framework/library names (React,Vue,Tailwind, etc.) and app/domain nouns (product, route, or component/file names). Split multi-feature tasks into separatesearchcalls. - Example: Search
"light dismiss dialog"or"responsive data table", not"dialog"(too terse),"responsive table dark mode"(compound — split into two searches), or"close React settings modal on outside click"(framework/app noise).
npx -y modern-web-guidance@latest search "<query>" --skill-version 2026_10_30-58d055df
Note: Returns
[{ "id", "description" }, ...]. Judge results by theirdescriptionfields:
- Match found: Call
retrievedirectly—do not also runlist.- No match on a web UI/CSS/DOM behavior (or broad UI audit): If
searchreturns[]or unrelated descriptions because your phrasing differed from the catalog (or your task spans multiple categories), runnpx -y modern-web-guidance@latest listonce to check if the pattern is covered under more general terminology.- Topic not covered: If no guide
descriptiondirectly matches your task, proceed with your implementation without retry loops or retrieving unrelated guides.
Step 2. Retrieve Best Practices
Once you have relevant id(s) from the search results, call retrieve to get the full guide(s)—including both specific use-case guides that match your task and any broader discipline guide (e.g., html, css, forms, accessibility, color, performance, security) that applies. You can pass multiple IDs separated by commas.
What ships with it
60 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- guides/accessibility/accessibility.md 50 KB
- guides/accessibility/accessible-error-announcement.md 7.0 KB
- guides/accessibility/accessible-generated-content.md 2.2 KB
- guides/accessibility/respect-os-text-scale.md 7.1 KB
- guides/built-in-ai/language-detection.md 3.6 KB
- guides/built-in-ai/language-model.md 16 KB
- guides/built-in-ai/prompt-api.md 16 KB
- guides/built-in-ai/summarizer.md 6.0 KB
- guides/built-in-ai/translator.md 7.2 KB
- guides/css/animate-to-intrinsic-sizes.md 5.3 KB
- guides/css/atrule-support-conditionals.md 5.7 KB
- guides/css/calculate-with-intrinsic-sizes.md 9.7 KB
- guides/css/child-state-based-styling.md 4.9 KB
- guides/css/content-based-styling.md 5.2 KB
- guides/css/css-layout.md 21 KB
- guides/css/css.md 12 KB
- guides/css/design-token-reactivity.md 5.8 KB
- guides/css/dynamic-sibling-styling.md 3.6 KB
- guides/css/fluid-scaling.md 3.0 KB
- guides/css/individual-transform-properties.md 3.6 KB
- guides/css/overflow-clipping-control.md 8.1 KB
- guides/css/reduce-style-repetition.md 3.9 KB
- guides/css/responsive-design.md 1.4 KB
- guides/css/selector-atrule-combinations.md 3.6 KB
- guides/css/size-aware-styling.md 2.9 KB
- guides/css/style-parent-with-has.md 6.0 KB
- guides/css/usage-aware-component-variations.md 5.1 KB
- guides/forms/animated-select-picker.md 7.9 KB
- guides/forms/autofill-address-form.md 4.8 KB
- guides/forms/autofill-highlight-inputs.md 2.3 KB
- guides/forms/autofill-payment-form.md 9.6 KB
- guides/forms/autofill-sign-in-form.md 10 KB
- guides/forms/autofill-sign-up-form.md 11 KB
- guides/forms/brand-consistent-forms.md 8.3 KB
- guides/forms/branded-select-styling.md 5.6 KB
- guides/forms/custom-select-picker-layouts.md 7.4 KB
- guides/forms/form-fields-automatically-fit-contents.md 5.9 KB
- guides/forms/forms.md 15 KB
- guides/forms/ime-safe-enter-submit.md 6.3 KB
- guides/forms/required-field-feedback.md 6.8 KB
- guides/forms/rich-media-picker.md 6.7 KB
- guides/forms/select-menu-interaction.md 5.4 KB
- guides/forms/slider.md 6.5 KB
- guides/forms/sms-otp-form.md 13 KB
- guides/forms/switch.md 2.5 KB
- guides/forms/validate-input-after-interaction.md 8.6 KB
- guides/html/accessible-web-components.md 5.1 KB
- guides/html/custom-elements.md 9.3 KB
- guides/html/form-associated-custom-elements.md 4.1 KB
- guides/html/html.md 18 KB
- guides/html/prerendering-custom-elements.md 3.6 KB
- guides/html/shadow-dom.md 3.8 KB
- guides/html/styling-web-components.md 8.7 KB
- guides/html/web-components.md 6.6 KB
- guides/js/calculate-event-differentials.md 8.3 KB
- guides/js/capture-location-agnostic-data.md 9.7 KB
- guides/js/coordinate-global-events.md 4.0 KB
- guides/js/sort-high-precision-timestamps.md 6.6 KB
- guides/js/support-global-calendar-systems.md 5.8 KB
- guides/performance/batch-analytics-events.md 6.4 KB
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 3d ago Changed · -64 lines · -58 tokens per session f81b42a337b4
- 18d ago Changed · +5 lines · +35 tokens per session 11be6f07942e
- 25d ago Changed · +8 lines e810a6759ce5
- 1mo ago Changed · -1 lines 0d22fb5b550d
- 2mo ago Changed · +10 lines 04c155936a74
- 2mo ago First seen · 115 lines · 233 tokens per session scan A 0e7aae3cc355
modern-web-guidance is a skill published in the GitHub repository GoogleChrome/modern-web-guidance (2,629 stars, last pushed 4d ago), licensed Apache-2.0. It adds 210 tokens to every session and 1,864 once invoked, about $0.0008 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
modern-web-guidance compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| modern-web-guidanceGoogleChrome/modern-web-guidance | Skill | 2.6k | 4d ago | Apache-2.0 | A | 210 | Claude Code |
| anti-slop-designsickn33/agentic-awesome-skills | Skill | 49k | yesterday | MIT | A | 34 | Claude Code |
| chakra-ui-builderchakra-ui/chakra-ui | Skill | 41k | yesterday | MIT | A | 214 | Claude Code, Codex |
| visual-ralphYeachan-Heo/oh-my-codex | Skill | 34k | 3d ago | MIT | A | 52 | Codex |
| open-design-setupcompozy/compozy | Skill | 2.8k | yesterday | MIT | A | 67 | Claude Code, Codex |
| edit-sitemicrosoft/power-platform-skills | Skill | 1.1k | yesterday | MIT | A | 104 | Claude Code |
| frontend-visual-qadaymade/claude-code-skills | Skill | 1.5k | yesterday | MIT | A | 125 | Claude Code, Codex |