Control UI
cursor/plugins
Build or adapt a local browser/CDP harness to drive and inspect a web, IDE, or Electron UI.
Standardizes visual audits, responsive design, and behavioral testing for web apps.
Install Common Web Visual Testing
$ npx skills add HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install HoangNguyen0403/agent-skills-standard common-web-visual-testing --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/HoangNguyen0403/agent-skills-standard.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/common/common-web-visual-testing .claude/skills/common-web-visual-testing && 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 "common-web-visual-testing" agent skill from https://github.com/HoangNguyen0403/agent-skills-standard/tree/develop/skills/common/common-web-visual-testing into .claude/skills/common-web-visual-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "common-web-visual-testing", 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/HoangNguyen0403/agent-skills-standard/tree/develop/skills/common/common-web-visual-testingType 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 HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install HoangNguyen0403/agent-skills-standard common-web-visual-testing --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/HoangNguyen0403/agent-skills-standard.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/common/common-web-visual-testing .agents/skills/common-web-visual-testing && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "common-web-visual-testing" agent skill from https://github.com/HoangNguyen0403/agent-skills-standard/tree/develop/skills/common/common-web-visual-testing into .agents/skills/common-web-visual-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "common-web-visual-testing", 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 HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install HoangNguyen0403/agent-skills-standard common-web-visual-testing --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/HoangNguyen0403/agent-skills-standard.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/common/common-web-visual-testing .cursor/skills/common-web-visual-testing && 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 "common-web-visual-testing" agent skill from https://github.com/HoangNguyen0403/agent-skills-standard/tree/develop/skills/common/common-web-visual-testing into .cursor/skills/common-web-visual-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "common-web-visual-testing", 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/HoangNguyen0403/agent-skills-standard.git --path skills/common/common-web-visual-testing--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 HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install HoangNguyen0403/agent-skills-standard common-web-visual-testing --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/HoangNguyen0403/agent-skills-standard.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/common/common-web-visual-testing .gemini/skills/common-web-visual-testing && 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 "common-web-visual-testing" agent skill from https://github.com/HoangNguyen0403/agent-skills-standard/tree/develop/skills/common/common-web-visual-testing into .gemini/skills/common-web-visual-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "common-web-visual-testing", 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 HoangNguyen0403/agent-skills-standard common-web-visual-testingInstalls 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 HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/HoangNguyen0403/agent-skills-standard.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/common/common-web-visual-testing .github/skills/common-web-visual-testing && 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 "common-web-visual-testing" agent skill from https://github.com/HoangNguyen0403/agent-skills-standard/tree/develop/skills/common/common-web-visual-testing into .github/skills/common-web-visual-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "common-web-visual-testing", 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 HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install HoangNguyen0403/agent-skills-standard common-web-visual-testing --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/HoangNguyen0403/agent-skills-standard.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/common/common-web-visual-testing .opencode/skills/common-web-visual-testing && 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 "common-web-visual-testing" agent skill from https://github.com/HoangNguyen0403/agent-skills-standard/tree/develop/skills/common/common-web-visual-testing into .opencode/skills/common-web-visual-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "common-web-visual-testing", 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
common-web-visual-testing- GitHub stars
- 572
- Token cost
- ~760 tokens
- SKILL.md length
- 227 words
- Files
- 6 (incl. references)
- Skills in repo
- 211
- Repo updated
- First seen
- Licence
- MIT
At a glance
Standardizes visual audits, responsive design, and behavioral testing for web apps.
- Works in 3 steps: Baseline (Before): Capture snapshot… → Implementation (After): Capture same… → Audit: Compare state for regression,…
- Verify a web UI fix
- SKILL.md covers Priority: P1 (HIGH), 🧪 Testing Mindset…, 📋 Scenario Matrix and 🚫 Anti-Patterns, plus 2 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Common Web Visual Testing is an agent skill from HoangNguyen0403/agent-skills-standard. Standardizes visual audits, responsive design, and behavioral testing for web apps. Use to verify a web UI fix or cross-browser behavior; defer backend API refactors, Playwright installation/tooling setup, and Appium/mobile automation.
Its SKILL.md is about 760 tokens, which your agent loads only when the skill is triggered. The skill folder holds 7 other files, including reference files (for example `evals/evals.json`, `references/diagnostic-decoder.md` and `references/dom-snapshot-vs-screenshot.md`).
It sits in Frontend & Design, covering Visual regression testing, Frontend development and Browser testing. It works with Playwright. The repository describes itself as: A collection of Agent Skills Standard and Best Practice for Programming Languages, Frameworks that help our AI Agent follow best practies on frameworks and programming laguages. The licence is MIT.
When your agent uses it
- Verify a web UI fix
- Cross-browser behavior
- Defer backend API refactors
- Playwright installation/tooling setup
Example prompts
- “Use the common-web-visual-testing skill to standardiz visual audits, responsive design, and behavioral testing for web apps”
- “/common-web-visual-testing”
Workflow steps
3 steps, taken from the first numbered list in SKILL.md.
- Baseline (Before): Capture snapshot --aria + screenshot prod/main.
- Implementation (After): Capture same local/feature.
- Audit: Compare state for regression, CLS, Aria drift.
What it can do on your machine
Read from SKILL.md and the folder at commit b529c2d. 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
No URLs in SKILL.md.
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
Common Web Visual Testing loads about 760 tokens when it runs, and up to ~4.8k if it reads all its reference files. Until then it costs about 65 tokens; SKILL.md has 227 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 HoangNguyen0403/agent-skills-standard at commit b529c2d, republished under its MIT licence (© HoangNguyen0403). 227 words, ~760 tokens.
Download SKILL.mdSave it as
.claude/skills/common-web-visual-testing/SKILL.md (or your agent's skills folder). This skill also uses 5 other files; get the full folder from GitHub.- name
- common-web-visual-testing
- description
- Standardizes visual audits, responsive design, and behavioral testing for web apps. Use to verify a web UI fix or cross-browser behavior; defer backend API refactors, Playwright installation/tooling setup, and Appium/mobile automation.
🌐 Web Visual & Behavioral Testing
Priority: P1 (HIGH)
[!IMPORTANT] Tier 2 (Methodology): Strategy web UI/UX audit. Tier 3 (Domain): Responsive, A11y (WCAG), Browser Engine quirk.
🧪 Testing Mindset (Comparative Audit)
Visual test best as Comparative Audit loop:
- Baseline (Before): Capture
snapshot --aria+screenshotprod/main. - Implementation (After): Capture same local/feature.
- Audit: Compare state for regression, CLS, Aria drift.
Responses must label the two captures as Before and After (or Baseline and Fixed) and include the diff and neighboring-element side-effect check.
📋 Scenario Matrix
| Change Type | Scenarios to Run |
|---|---|
| CSS/Layout | Responsive Audit + Hover + CLS Check |
| Forms/Input | Validation Msg + Focus State + Error Boundary |
| Navigation | URL Sync + Sticky Header + Back-Button Persistence |
| Assets/Fonts | Lazy Load + Icon Check + LCP Audit |
| Accessibility | Tab Order + Aria-Snapshot + Color Contrast |
🚫 Anti-Patterns
- Single-Viewport: Never verify Desktop only. Check Mobile (375px) + Tablet (768px).
- Ignore Layout Shift: Check loading state (skeleton) → no page jump.
- Unmasked Dynamic: MUST mask timestamp/balance via
--maskor JS (opacity: 0). Avoid "False Regression". - Blind Assertion: Use
playwright-cli snapshot --aria(CLI) orbrowser_snapshot(Playwright MCP) verify state before done.
📁 Evidence
Before/After pairs live in .playwright-cli/<session>/ as <AC|step>-before.png / <AC|step>-after.png plus matching .aria.txt. Driver rung and dir go in the walkthrough driver: / evidence_dir: lines.
- External Dependency: Mock/bypass 3rd-party (Chat, Analytics) → prevent flakiness.
🔗 References
- playwright-cli: playwright-cli
- Driver Ladder: driver-ladder — CLI first, Playwright MCP fallback, BLOCKED rule.
- Diagnostic Decoder: diagnostic-decoder
- DOM vs Screenshot: dom-snapshot-vs-screenshot
- Login & Data: login-and-test-data
- Scenario Details: scenarios
© HoangNguyen0403, 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 5 other files (references) in skills/common/common-web-visual-testing of HoangNguyen0403/agent-skills-standard.
- SKILL.md
- evals/evals.json
- references/diagnostic-decoder.md
- references/dom-snapshot-vs-screenshot.md
- references/login-and-test-data.md
- references/scenarios.md
Open the folder on GitHubat commit b529c2d
Compare with similar skills
Common Web Visual Testing 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 |
|---|---|---|---|---|---|---|
| Common Web Visual Testing this skillHoangNguyen0403/agent-skills-standard | 572 | — | ~760 | Automated safety check: Pass | MIT | |
| Control UIcursor/plugins | 11k | 2 repos | ~1.2k | Automated safety check: Pass | None | |
| UI Visual DebuggingNangoHQ/nango | 13k | — | ~1.3k | Automated safety check: Pass | Custom licence | |
| Browser QAaffaan-m/ECC | 277k | 2 repos | ~1k | Automated safety check: Pass | MIT | |
| Visual Diffbitovi/ai-enablement-prompts | 121 | — | ~2.9k | Automated safety check: Pass | MIT | |
| UI CraftMemTensor/memmy-agent | 2.1k | — | ~2.9k | Automated safety check: Pass | MIT |
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A skill your agent uses when modifying or visually debugging Nango frontend UI, including packages/webapp, packages/connect-ui, browser interactions, screenshots, and visual regressions.
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Run automated post-deploy UI verification with a browser automation MCP (claude-in-chrome, Playwright, or Puppeteer): console-error and Core Web Vitals smoke checks, form and auth-flow interaction…
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Bulk-regenerate broken test selectors after a UI refactor or redesign.
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Questions about Common Web Visual Testing
What does Common Web Visual Testing do?
Standardizes visual audits, responsive design, and behavioral testing for web apps. Common Web Visual Testing is an agent skill from HoangNguyen0403/agent-skills-standard. Standardizes visual audits, responsive design, and behavioral testing for web apps.
When should I use Common Web Visual Testing?
Common Web Visual Testing fits situations like: verify a web UI fix; cross-browser behavior; defer backend API refactors; playwright installation/tooling setup.
How do I install Common Web Visual Testing in Claude Code?
Run `npx skills add HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a claude-code`. Or copy the skill folder (skills/common/common-web-visual-testing in HoangNguyen0403/agent-skills-standard) into .claude/skills/common-web-visual-testing in your project. Claude Code loads it when a task matches its description.
How do I install Common Web Visual Testing in Codex?
Run `npx skills add HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a codex`. Or copy the skill folder (skills/common/common-web-visual-testing in HoangNguyen0403/agent-skills-standard) into .agents/skills/common-web-visual-testing in your project. Codex loads it when a task matches its description.
Can I use Common Web Visual Testing 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 HoangNguyen0403/agent-skills-standard --skill common-web-visual-testing -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/common-web-visual-testing, .gemini/skills/common-web-visual-testing, .github/skills/common-web-visual-testing and .opencode/skills/common-web-visual-testing in your project.
What does Common Web Visual Testing need to run?
SKILL.md names no scripts, command-line tools or credentials: Common Web Visual Testing is instructions for the agent only.
Does Common Web Visual Testing access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Common Web Visual Testing 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 Common Web Visual Testing use?
Common Web Visual Testing 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 Common Web Visual Testing use?
About 760 tokens (SKILL.md is roughly 3k 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 4.1k tokens, read only when the agent opens those files.
What are the alternatives to Common Web Visual Testing?
Skills that share tags, products or a category with Common Web Visual Testing: Control UI (cursor/plugins, 11k stars), UI Visual Debugging (NangoHQ/nango, 13k stars), Browser QA (affaan-m/ECC, 277k stars) and Visual Diff (bitovi/ai-enablement-prompts, 121 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Common Web Visual Testing?
HoangNguyen0403 (a GitHub user) maintains it in HoangNguyen0403/agent-skills-standard, which has 572 GitHub stars. The repository holds 211 skills in this directory. The repository was last updated on October 9, 2026.
Source: HoangNguyen0403/agent-skills-standard on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.