Web Validator by DigestSEO

Name: Web Validator by DigestSEO
Author: AKzar1el

by AKzar1elversion 1.3.47i★ –iComputer or cloud

Registry nameio.github.AKzar1el/mcp-web-validator

Install

Overview

Description from the maker (original English)

Audit public webpages and supplied markup for HTML, CSS, SEO, JSON-LD, and link issues.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi3 of 3 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Computer or cloud
Transport: stdio, Streamable HTTP
Category: Marketing & social media

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 3 of 3 passed
Runs on the maker’s server: what you ask it goes through their server.
Can do 8 things (tools) validate_html, validate_css, audit_seo_metadata, validate_schema_markup …
The registry lists no key to fill in.

You need

Runs in the cloudNothing to install; it connects over the internet
npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Works in Claude on the web, desktop and mobile:

Open Settings → Connectors
Press Add custom connector
Paste the address below and press Add
If it asks you to sign in, sign in with the maker

https://web-validator-mcp.digestseo.com/mcp

Or run it on your computer

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "web-validator": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-web-validator"
      ]
    }
  }
}

Run this in your terminal

claude mcp add --transport http web-validator https://web-validator-mcp.digestseo.com/mcp

Or run it on your computer

claude mcp add web-validator -- npx -y mcp-web-validator

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "web-validator": {
      "url": "https://web-validator-mcp.digestseo.com/mcp"
    }
  }
}

Or run it on your computer

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "web-validator": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-web-validator"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "web-validator": {
      "type": "http",
      "url": "https://web-validator-mcp.digestseo.com/mcp"
    }
  }
}

Or run it on your computer

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "web-validator": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mcp-web-validator"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

ChatGPT connects only to servers on the internet:

Open ChatGPT on the web → Settings → Connectors (Apps)
Press Create or Add (some plans need Developer mode under Advanced first)
Paste the address below, give it a name and save
If it asks you to sign in, sign in with the maker

https://web-validator-mcp.digestseo.com/mcp

Menu names can differ slightly by plan and over time.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Tool names and descriptions exactly as the server reported them on Nov 7, 2026. The maker wrote them, not us; we show them as plain text.

validate_html
Use this when raw HTML markup is supplied. Sends that markup to the Nu HTML Checker hosted at validator.nu and returns validation messages. For a live URL, use audit_public_webpage.
validate_css
Use this when raw CSS source is supplied. Parses it inside the Worker and returns syntax messages without contacting an external service.
audit_seo_metadata
Use this for a focused SEO/accessibility-signal check of supplied HTML. It does not fetch a live webpage; use audit_public_webpage for a URL.
validate_schema_markup
Use this for a focused JSON-LD syntax check of supplied HTML. It parses JSON only and does not validate Schema.org vocabulary semantics.
check_broken_links
Use this for a focused check of up to 20 public HTTP(S) links found in supplied HTML. It does not fetch base_url, follow redirects, or retain response bodies.
generate_validation_report
Use this when HTML markup is already supplied. Combines Nu HTML validation with local CSS, SEO, accessibility-signal, and JSON-LD syntax checks. It does not fetch a webpage from base_url; use audit_public_webpage for a live URL.
audit_public_webpage
Use this when the user provides one live public webpage URL. Fetches one bounded static HTML response, then runs HTML validation, SEO/accessibility-signal, and JSON-LD syntax checks. It checks links only when requested and does not crawl, execute JavaScript, authenticate, or fetc
audit_public_site
Use this for a bounded, sitemap-first audit of a public website the user owns or is authorized to inspect. It fetches at most 8 same-origin HTML pages per call, respects robots.txt, and returns compact page summaries plus deduplicated findings. It does not recursively follow HTML

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account AKzar1el, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
✓ Pass
Endpoint responds
Responded in 239 ms (HTTP 200)
– Not applicable
Sign-in with OAuth
No sign-in needed
✓ Pass
No hidden instructions in tool descriptions
Read 8 tool descriptions and found no hidden instructions to the AI

Compared with others in Marketing & social mediai

More stars than 0% of the other 2985 servers in this category
Published to the registry more recently than 75% of the other 2985 servers in this category
Basic checks equal to or better than 100% of the other 2985 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Web Validator by DigestSEO safe?

It passed 3 of 3 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

Either way works: install it on your computer or connect to the cloud version.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.3.47) reached the registry 11 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: MCP YouTube Transcript, Google Analytics MCP, BibiGPT YouTube Video Summarizer

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Web Validator by DigestSEO

An MCP server for HTML and CSS validation, technical SEO and accessibility checks, JSON-LD syntax validation, broken-link checks, and responsive screenshots. It is part of the DigestSEO suite of open-source SEO tools.

Product: digestseo.com/validator-mcp
Engineering case study: DigestSEO MCP Suite — AI visibility, Search Console, web validation, and trend intelligence
Documentation: this README
Support: digestseo.com/support
Privacy: digestseo.com/privacy

Choose the right surface

This repository contains two deliberately separate MCP surfaces:

Surface	Transport	Best for	Access and side effects
Local npm server	stdio	Claude Desktop, Cursor, and other local MCP clients	Can read user-selected workspace files, contact validation and link targets, and write screenshot files.
Hosted app	Streamable HTTP	ChatGPT and remote MCP clients	Can fetch one authorized public HTML page, run a bounded sitemap-first site audit, or process supplied markup. It cannot access local files, authenticate, recursively crawl links, execute page JavaScript, or create screenshots.

Local installation:

npx -y mcp-web-validator

Hosted endpoint:

https://web-validator-mcp.digestseo.com/mcp

Requirements

Node.js 22.12.0 or newer
An MCP client that supports stdio, or a client that supports Streamable HTTP for the hosted endpoint

The validation, SEO, schema, link, and report tools do not download a browser during installation. The local screenshot.capture tool installs its pinned headless browser into Puppeteer's cache on first use, then reuses that browser for later screenshots. Set PUPPETEER_CACHE_DIR if you need a custom cache location.

Tools

The npm package exposes these exact runtime tool names:

Tool	Purpose	Network or filesystem behavior
`html.local`	Validate a local HTML or XHTML file.	Reads the selected file and submits its markup to the external W3C Nu HTML Checker at `validator.w3.org/nu/`; `.xhtml` paths use `application/xhtml+xml` parsing semantics.
`html.url`	Validate the markup returned by a public URL.	Fetches the URL, then submits the returned markup to the external Nu checker.
`css.local`	Validate a local CSS file.	Reads the selected file and submits its CSS to the external W3C Jigsaw CSS Validator.
`seo.metadata`	Audit titles, descriptions, canonical tags, robots noindex directives, headings, viewport metadata, image alt attributes, and Open Graph metadata.	Processes supplied HTML locally.
`links.broken`	Check links extracted from supplied HTML.	Sends bounded HTTP requests to eligible public links.
`schema.markup`	Parse JSON-LD blocks and report JSON syntax errors.	Processes supplied HTML locally.
`report.validation`	Combine HTML/XHTML, optional CSS, SEO, JSON-LD, and bounded link checks in a Markdown report.	Reads selected files, contacts the validators, and checks eligible public links found in the markup; `.xhtml` inputs use XHTML parsing semantics for Nu validation.
`screenshot.capture`	Capture desktop, tablet, mobile, or custom viewport screenshots.	Opens a selected local file or eligible public URL and writes PNG files to the selected output directory; existing matching files may be replaced.

For direct Node.js integrations, auditSeoMetadata(html, xRobotsTag) and auditSeoMetadataDetailed(html, xRobotsTag) from dist/seo-auditor.js accept an optional caller-observed X-Robots-Tag HTTP response-header value. Separate multiple header fields with newlines. This inspection is offline and never fetches headers; the MCP seo.metadata tool still analyzes supplied HTML only.

Hosted app tools

The hosted app exposes eight tools:

Tool	Purpose
`audit_public_webpage`	Fetch one authorized public HTML page and run the combined HTML, SEO/accessibility-signal, and JSON-LD syntax audit. Link checks are optional.
`audit_public_site`	Run a bounded sitemap-first audit of up to eight authorized, same-origin public pages. It respects `robots.txt`, returns compact page coverage and deduplicated findings, and does not run site-wide link checks.
`validate_html`	Validate raw HTML markup already supplied in the conversation.
`validate_css`	Parse supplied CSS for syntax errors inside the Worker.
`audit_seo_metadata`	Audit supplied HTML for covered on-page SEO, robots noindex, and accessibility signals.
`validate_schema_markup`	Check JSON-LD blocks in supplied HTML for JSON syntax errors.
`check_broken_links`	Check up to 20 authorized public links extracted from supplied HTML.
`generate_validation_report`	Combine the checks for supplied markup; `base_url` resolves relative links but does not fetch a page.

audit_public_webpage follows at most three validated redirects, accepts a bounded text/html response, and records the final URL. It does not crawl additional pages, execute JavaScript, authenticate, or fetch linked stylesheets and assets. audit_public_site first locks the final public origin, then reads bounded robots.txt plus same-origin XML Sitemap, RSS 2.0, Atom 1.0, and plain-text sitemap representations before auditing at most eight eligible sitemap pages in one call. Robots discovery may follow up to five validated public redirects across authorities, as defined by the robots protocol; the resulting rules and relative Sitemap directives are still interpreted for the originally audited authority. Sitemap entries and audited pages remain same-origin, and private/reserved destinations, credentials, custom ports, service self-fetches, and HTTPS-to-HTTP redirect downgrades are rejected. The tool never follows HTML links or external sitemap entries; use page_offset when the response says more eligible pages remain. The fetched HTML is sent to https://html5.validator.nu/, the same external Nu HTML Checker used by validate_html and the report tool. CSS parsing, SEO analysis, and JSON-LD parsing run inside the DigestSEO Worker. Optional link checks make capped HEAD requests, with a bounded GET fallback where necessary, to eligible public HTTP(S) URLs; link redirects are reported but not followed. The site tool intentionally does not perform site-wide link checking. The hosted app does not retain tool inputs, fetched HTML, or results.

Privacy Policy

Only validate files, markup, and public webpages that you own or are authorized to inspect. Public page URLs can contain sensitive query values, so remove tokens and private identifiers before submitting them. Do not submit passwords, API keys, access tokens, payment data, health data, private source code, or other sensitive personal data.

The local server runs with the same operating-system permissions as its MCP client. Review tool inputs before approving file access, outbound validation, link checking, or screenshot creation. The hosted app has no access to your local filesystem.

See the published privacy policy for data-handling details and SECURITY.md for private vulnerability reporting.

Configure a local client

Claude Desktop

Add the server to claude_desktop_config.json:

Windows: %APPDATA%\Claude\claude_desktop_config.json
macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

"mcpServers": { "mcp-web-validator": { "command": "npx", "args": ["-y", "mcp-web-validator"] } } }

Restart Claude Desktop after saving the configuration.

Cursor and compatible clients

Create a command/stdio MCP server with:

npx -y mcp-web-validator

This repository also includes a Cursor Marketplace plugin manifest. After the plugin is published, install Web Validator by DigestSEO from Cursor's Marketplace or add the repository from Cursor's plugin UI. The plugin bundles the same local stdio server and does not require API keys or environment variables.

Visual Studio Code with GitHub Copilot

In VS Code, run MCP: Add Server from the Command Palette and choose Command (stdio) with npx -y mcp-web-validator. Or add the following to your own workspace's .vscode/mcp.json (VS Code format):

"servers": { "mcp-web-validator": { "type": "stdio", "command": "npx", "args": ["-y", "mcp-web-validator"] } } }

For a remote-only connection, use this server entry instead (no local Node.js required, but local-file and screenshot tools are unavailable):

"servers": { "mcp-web-validator-hosted": { "type": "http", "url": "https://web-validator-mcp.digestseo.com/mcp" } } }

Open MCP: List Servers to start/check the connection. In Copilot Agent chat, ask it to run seo.metadata on an HTML snippet you provide (input field htmlContent) and report its metadata issues. This is an offline, no-network smoke test of the local stdio server; it should return structured issues and totalIssues without contacting W3C or fetching a webpage. Use the local server for this check, since the hosted surface has different tool names.

The repository also contains a portable root .mcp.json for compatible Copilot harness clients. Its top-level key is mcpServers, not servers; do not copy that object unchanged into .vscode/mcp.json. VS Code's MCP configuration reference explains the file formats and supported scopes. Review tool permissions before allowing outbound validation or filesystem-writing screenshot calls.

OpenAI Codex

Codex CLI can add the published local stdio package directly:

codex mcp add mcp-web-validator -- npx -y mcp-web-validator

Or add the existing hosted Streamable HTTP surface instead:

codex mcp add mcp-web-validator-hosted --url https://web-validator-mcp.digestseo.com/mcp

Verify either configuration with:

codex mcp list

The local package includes workspace-file validation and responsive screenshot capture. The hosted surface is remote-only and cannot access local files or create screenshots.

Gemini CLI

Gemini CLI supports local stdio MCP servers. Add the published package with:

gemini mcp add mcp-web-validator npx -y mcp-web-validator

This writes the server definition to Gemini CLI's MCP configuration. No API keys or environment variables are required by Web Validator.

GitHub Copilot CLI

Add the published local stdio server with:

copilot mcp add mcp-web-validator -- npx -y mcp-web-validator

When Copilot CLI is started inside a clone of this repository, it can also discover the checked-in root .mcp.json, which already points mcp-web-validator at npx -y mcp-web-validator.

Kiro

[](https://kiro.dev/launch/mcp/add?name=mc

Only the beginning is shown; read the rest in the repo

Web Validator by DigestSEO

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Or run it on your computer

Or run it on your computer

Or run it on your computer

Or run it on your computer

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Marketing & social mediai

Common questions

Alternatives

MCP YouTube Transcript

Google Analytics MCP

BibiGPT YouTube Video Summarizer

README from the maker

Web Validator by DigestSEO

Choose the right surface

Requirements

Tools

Hosted app tools

Privacy Policy

Configure a local client

Claude Desktop

Cursor and compatible clients

Visual Studio Code with GitHub Copilot

OpenAI Codex

Gemini CLI

GitHub Copilot CLI

Kiro