Website SEO Audit: on-page checker, score & tech stack

Audit every page of a website for on-page SEO in one run. Each page gets a 0–100 score and a plain-English fix list. You also get a site summary: the most common problems, duplicate titles and descriptions, the 10 worst pages, and the site's tech stack.

• Just type the domain: pages come from the sitemap (or by following internal links if there is none). Or paste specific URLs.
• What it checks: title and meta description (missing or too long or short), H1 count, canonical, noindex (meta and header), lang, mobile viewport, images without alt text, Open Graph, schema.org types (JSON-LD), word count / thin content, HTTPS, response time, page size, internal and external link counts, hreflang.
• Tech stack detection: WordPress, Shopify, Webflow, Wix, Next.js, Google Analytics, GTM, Cloudflare, Stripe, and 20+ more, from headers and HTML.
• Fast, polite, and safe: plain HTTP, no browser, obeys each site's robots.txt, at most 4 requests at once to a site.

Sample output (real, plausible.io, Oct 2026)

Site summary (20 pages):

{
  "type": "summary",
  "website": "plausible.io",
  "pagesAudited": 20,
  "averageScore": 90.1,
  "pagesWithIssue": { "images-missing-alt": 20, "title-too-long": 16, "description-too-long": 6 },
  "topFixes": [
    "Some images have no alt text. (20 pages)",
    "Title is over 60 characters and will be cut off in Google. (16 pages)",
    "Meta description is over 160 characters and will be cut off. (6 pages)"
  ],
  "duplicateTitles": 0,
  "duplicateDescriptions": 0,
  "worstPages": [{ "url": "https://plausible.io/google-analytics-script-size", "score": 87 }],
  "technologies": ["Plausible"]
}

One page (fields shortened):

{
  "type": "page",
  "url": "https://plausible.io/google-analytics-script-size",
  "status": 200,
  "score": 87,
  "issues": ["title-too-long", "description-too-long", "images-missing-alt"],
  "fixes": [
    "Title is over 60 characters and will be cut off in Google.",
    "Meta description is over 160 characters and will be cut off.",
    "Some images have no alt text."
  ],
  "title": "How much JavaScript does Google Analytics add to your site? | Plausible Analytics",
  "titleLength": 81,
  "metaDescriptionLength": 166,
  "h1Count": 1,
  "wordCount": 1040,
  "imagesMissingAlt": 1,
  "schemaTypes": ["BlogPosting"],
  "responseMs": 508,
  "technologies": ["Plausible"]
}

Every page row also includes the full meta description, H1 text, canonical, robots, lang, Open Graph tags, Twitter card, hreflang, link counts, and page size.

How to use

1. Add websites (whole-site audit) and/or URLs (specific pages).
2. Set max pages per website to cap the cost.
3. Run, then export from the Dataset tab (JSON, CSV, Excel, or API). Schedule it monthly to track scores.

Sample input

{ "websites": ["yoursite.com", "competitor.com"], "maxPagesPerWebsite": 50 }

Pricing

• $0.007 per page audited ($7 per 1,000 pages). The site summary is free.
• No start fee. Unreachable pages, and pages a site's robots.txt disallows, cost nothing. 50 pages = $0.35.

Who it's for

• Site owners and marketers: a prioritized fix list without a $100/month SEO suite
• Agencies and freelancers: client and prospect audits in minutes; compare a client with competitors
• Lead generation: find sites on a given platform (e.g. WordPress, Shopify) with weak SEO
• Developers and AI agents: structured on-page data for any URL list

Works well with

• Broken Link Checker: 404s and redirect chains on the same site
• Sitemap URL Extractor: every URL a site lists
• WHOIS Domain Lookup: registrar, expiry, and DNS

FAQ

Does it run JavaScript? No. It audits the HTML the server sends, which is what most search engines see first. Sites built entirely in JavaScript will show thin content and missing tags. How is the score calculated? It starts at 100, and each issue subtracts a fixed amount (for example, noindex −30, missing title −20, missing H1 −10, title too long −5). It's a fix priority, not a Google ranking factor. Does it check Core Web Vitals? No. Only server response time and HTML size.

More tools from the same studio: Kramer Labs.

Data source and responsible use

This Actor reads the public HTML a server sends, the same as a search engine, and follows each site's robots.txt (RFC 9309). It doesn't log in, bypass blocks or CAPTCHAs, or collect personal data. Use it on your own or your clients' sites, or for competitive research on public pages, and follow the terms of the sites you audit.