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Check your webpage HTML

Check a public page against the html-validate recommended ruleset, with seven documented style and SEO rules disabled.

Guest includes 50 lifetime app requests. Create a free account for 100 app requests each calendar month. One allowance across every app, in your browser and your agent.One allowance across every app, in your browser and your agent. Manage usage

Webpage HTML Check

Connect agent

Guest access is available after setup. Full account linking verified by PowMCP: Claude only.

HTML Check

Standards validation of one page's markup against the html-validate recommended ruleset.

Usually finishes within 30 seconds.

Add Webpage HTML Check to your agent

Connect this app on its own. Add other PowMCP apps whenever your agent needs another job done.

Open the apps workspace A glowing app tile clicking into a slot on a dark agent device, with the PowMCP app box behind it

Connect directly

Choose your agent. Each button opens a new tab with only this app's endpoint ready to add.

Use another agent

Copy one ready-to-send prompt for any agent that supports remote MCP connections.

Manual endpoint, JSON, and terminal commands

For clients that require manual configuration, use this app-only endpoint, its JSON entry, or one terminal command.

ChatGPT: enable Developer mode in Settings → Security and login, then add this MCP endpoint from the Plugins page. Availability depends on your account and workspace policy. PowMCP has not yet verified ChatGPT account linking. OpenAI setup guide

https://powmcp.com/webpage-html-check/mcp
{
  "mcpServers": {
    "powmcp-webpage-html-check": {
      "type": "http",
      "url": "https://powmcp.com/webpage-html-check/mcp"
    }
  }
}

Terminal agents add this app with one command:

Claude Code
claude mcp add --transport http powmcp-webpage-html-check https://powmcp.com/webpage-html-check/mcp
Codex CLI
codex mcp add powmcp-webpage-html-check --url https://powmcp.com/webpage-html-check/mcp
Gemini CLI
gemini mcp add --transport http powmcp-webpage-html-check https://powmcp.com/webpage-html-check/mcp

Manage, disable, or remove this connection in your agent's own MCP settings. PowMCP does not label an external connection as installed without confirmation from that client.

Proof

What it does

The W3C-aligned html-validate recommended ruleset, seven style and SEO rules disabled and listed, run over any live page's markup

Validate any public webpage's markup for real: the app fetches the live page and runs the html-validate recommended ruleset with seven of its style and SEO rules disabled (all seven are named in the README; every conformance rule in the ruleset stays on; W3C-aligned, not the exhaustive W3C Nu checker), returning a markup score, a straight verdict on whether the page validates under that modified ruleset, the standards error and warning counts, and the worst-offending rules named as the things to fix.

Category
Developer Tools

Request cost1 completed result

Guests get 50 lifetime app requests. Free accounts get 100 each calendar month.

Tools in this app

01

HTML Check

html_check

Validates one public URL's markup against the html-validate recommended ruleset with seven of its style and SEO rules disabled (all seven are named in the README; W3C-aligned, not the exhaustive W3C Nu checker), returning a markup score, whether the page validates under that ruleset, HTML error and warning counts, and the most-violated markup rules. Usually done in about a second.

Webpage HTML Check questions

Scope and boundaries for Webpage HTML Check.

01What can I check with Webpage HTML Check?

Validate the live markup at https://example.com against the app's modified html-validate recommended ruleset.

02How should I read the result?

Read html.valid first: true means the page passed this modified html-validate recommended ruleset. Fix the most frequent rule in topRules, rerun, and continue until the error and warning counts clear. The result gives rule counts rather than element locations and is not the exhaustive W3C Nu validator, so it may identify priority without enough evidence to locate every fix.

03What are its limits?

The verdict is specific to html-validate's recommended ruleset with the app's seven documented style and SEO rules disabled. It is W3C-aligned but not the exhaustive W3C Nu checker, and checking one fetched page does not cover templates, routes, runtime states, accessibility, or site-wide behavior.