On-Page SEO Analyzer

How do I run a full on-page SEO audit of a page — title, meta, headings, images, links, content and keyword usage — with a score, without uploading my HTML?

Open AnyTool’s On-Page SEO Analyzer, paste your page’s HTML source (View Source / Ctrl+U), optionally add a target keyword, and it runs a complete on-page audit entirely in your browser. It checks the <title> and meta description (present + length), that there is exactly one H1 with a logical H2–H6 outline, every image’s alt text (counting missing ones), internal vs external links (and nofollow / empty-anchor / http links), content length, the canonical, robots/noindex, viewport, html lang, charset and JSON-LD structured-data presence. With a target keyword it checks whether the keyword is in the title, H1, first paragraph, meta description and URL, plus its body density. Each check is a pass / warn / fail with a concrete fix, grouped into Titles & Meta, Content & Headings, Images, Links and Technical, and everything rolls up into a weighted 0–100 score with a letter grade and a prioritized fix list. It is broader than a meta-tag checker — a whole-page audit. Honest caveat: it audits only the on-page factors in the HTML you paste against common best practices; it is guidance, not a ranking guarantee, and it cannot see off-page factors (backlinks, authority), real rendering or Core Web Vitals. Your HTML is never uploaded.

Full-page audit: title, meta, one-H1 + heading order, image alt, internal/external links, content length, canonical, robots, viewport, lang, JSON-LD
Optional target keyword checked in title, H1, first paragraph, meta description, URL + body density (flags absence AND stuffing)
Weighted 0–100 score + letter grade, grouped pass / warn / fail checks with a fix each, and a prioritized to-do list
100% client-side — your page HTML is parsed in the browser and never uploaded; safe for staging / unreleased pages
Honest: guidance not a ranking guarantee; can’t see off-page factors, rendering or Core Web Vitals — paste your source

What is

On-page SEO audit

An on-page SEO audit reviews the elements within a single page’s own HTML — title, meta description, headings, image alt text, links, content and technical tags — against best practices and reports what to fix. It covers on-page factors only, not off-page signals like backlinks.

SEO & Web

Related terms

Title tagMeta descriptionH1 headingImage alt textInternal linkingCanonical URLStructured data

Frequently Asked Questions

An on-page SEO analyzer audits the factors inside a single page’s HTML: the title tag (present and ~50–60 chars), the meta description (~150–160 chars), a single H1 with a logical H2–H6 heading order, image alt text (flagging missing alt), internal versus external links (and nofollow / empty anchors), content/word count, the canonical link, the robots/noindex directive, the mobile viewport, the html lang attribute, character encoding and JSON-LD structured-data presence. AnyTool’s tool grades each as pass, warn or fail with a specific fix, then rolls everything into a weighted 0–100 score — all computed in your browser from the HTML you paste, with nothing uploaded.

It checks a page’s title, meta description, headings (one H1), image alt text, internal and external links, content length, canonical, viewport, language and structured data, and gives a score.

The sibling Meta Tag Analyzer focuses on the meta and link tags in the document head (title, description, robots, canonical, viewport, Open Graph, Twitter Card). The On-Page SEO Analyzer is broader: it also audits the body — the H1 and heading outline, image alt text, internal versus external links, content length and how a target keyword is used across the title, H1, first paragraph and body — and combines all of it into a single weighted score with a prioritized fix list. Use the meta analyzer for a deep meta-tag pass and this one for a whole-page audit.

A meta tag analyzer only checks the tags in the head. This audits the whole page — headings, images, links, content and keyword usage too — and gives one overall score.

The analyzer runs 100% client-side. The HTML you paste is parsed with the browser’s own DOMParser and audited locally — nothing is fetched, uploaded, logged or crawled, and there is no server proxy. That makes it safe for staging, unreleased or internal pages that you cannot or do not want to expose to an online checker. Because most live sites block cross-origin fetches (CORS) and there is no proxy, the reliable path is to open your page, copy its source (View Source / Ctrl+U) and paste it in.

Yes — your HTML is parsed in your browser and never uploaded, so it is safe for staging, unreleased or internal pages.

A high score means the on-page fundamentals present in your HTML follow common best practices — a strong foundation, but not a ranking guarantee. The tool cannot see off-page factors (backlinks, domain authority, brand signals), how the page actually renders (JavaScript-injected content, layout), or your Core Web Vitals and real page speed, and Google frequently rewrites titles and snippets. The length and count thresholds are widely-cited approximations, not hard rules. For a full site crawl, rendered analysis and performance data, pair it with Screaming Frog, Google Search Console and PageSpeed Insights.

No. It’s guidance on the on-page basics in your HTML. Rankings also depend on off-page factors, rendering and Core Web Vitals it can’t see.

Paste a page’s HTML source and run a full on-page SEO audit — title, meta description, headings (one H1), image alt text, internal/external links, content length, canonical, robots, viewport, language, charset and structured data — with a weighted 0–100 score, grouped pass / warn / fail checks, an optional target-keyword usage check and a prioritized fix list. 100% client-side; your page HTML is never uploaded.

Features

Full-page audit grouped into Titles & Meta / Content & Headings / Images / Links / Technical, each check a pass / warn / fail with a fix
Extracts stats: word count, heading outline, one-H1 + level order, images + missing alt, internal vs external links, canonical / viewport / lang / JSON-LD
Optional target keyword checked in title, H1, first paragraph, meta description and URL + body density (flags absence AND stuffing)
Weighted 0–100 score with a letter grade and a prioritized to-do list (failures first); reuses the shared text-stats engine for word count
100% client-side — page HTML parsed with DOMParser and never uploaded; honest guidance-not-a-guarantee / can’t-see-off-page-or-CWV note

PriceFree

CategorySEO & Web

PlatformAll (browser-based)

PrivacyPage HTML is parsed locally with DOMParser and never uploaded; no page is crawled (no server proxy)

Input: Paste your page’s full HTML source (View Source / Ctrl+U), Optional target keyword, Optionally fetch a CORS-enabled / same-origin URL

Output: Overall 0–100 score + letter grade + verdict, Grouped checks (Titles & Meta / Content & Headings / Images / Links / Technical) with fixes, Page-stats panel + heading outline, Target-keyword usage panel, Prioritized fix list + copyable report

Detailed Explanation

How It Works

What the On-Page SEO Analyzer Does

On-Page SEO Analyzer is a 100% client-side tool that runs a full on-page SEO audit of a single page from its pasted HTML source. Unlike a meta-tag-only checker, it audits the whole page: the <title> and meta description (present and length), that there is exactly one H1 with a logical H2–H6 outline, every image’s alt text (counting missing ones), internal vs external links (and nofollow, empty-anchor and insecure http links), content length, the canonical, the robots/noindex directive, the mobile viewport, the html lang attribute, character encoding and JSON-LD structured-data presence. An optional target keyword is checked in the title, H1, first paragraph, meta description and URL, with its body density. Every check is a pass / warn / fail with a concrete fix, grouped into Titles & Meta, Content & Headings, Images, Links and Technical, and everything rolls up into a weighted 0–100 score with a letter grade and a prioritized fix list.

Full-page audit, not just meta tags: title, meta, headings, image alt, links, content, canonical, robots, viewport, lang, charset, JSON-LD
Exactly-one-H1 and heading-order checks; internal vs external link counts with nofollow / empty-anchor / http flags
Optional target keyword checked in title, H1, first paragraph, meta description and URL, plus body density (flags absence and stuffing)
Weighted 0–100 score + letter grade, grouped pass / warn / fail checks with a fix each, and a prioritized to-do list
Reuses the shared text-stats engine for word count; parses with the browser’s DOMParser (regex fallback so it never throws)

Methodology

How the Audit and Score Are Computed

The engine (onPageSeoEngine.ts, no new dependency) parses the pasted HTML with the browser’s DOMParser, extracting the title, meta description, canonical, robots, viewport, lang and charset; every heading with its level; every image and whether it has an alt attribute; and every <a href> classified as internal (relative / root-relative) or external (absolute), with its rel (nofollow) and anchor text. Non-navigational hrefs (mailto:, tel:, javascript:, bare #fragments) are excluded from the link counts. Visible body text is read after stripping script / style / noscript, and word count comes from the shared textStats() façade. Each check carries a weight reflecting how important the on-page factor is; the score is the weighted percentage of checks passed, where a warning counts as half credit and a failure as zero, mapped to a letter grade (A–F). Suggestions are sorted failures-first, then by weight, so the highest-impact fixes surface at the top.

DOMParser-based extraction with a regex fallback for non-DOM environments (SSR / worker)
Links classified internal vs external; mailto / tel / javascript / #fragment excluded from counts
Body text stripped of script/style/noscript; word count via the shared textStats() engine
Weighted score: pass = full weight, warn = half, fail = zero → 0–100 and an A–F grade
Prioritized fix list orders failures first, then by weight (most impactful on top)

Limitations

Honest Scope and Limitations

This audits only the on-page factors present in the HTML you paste, against widely-cited best practices — it is guidance, not a ranking guarantee. It cannot see off-page factors (backlinks, domain authority, brand signals), how the page actually renders (JavaScript-injected content, layout, visual hierarchy), or your Core Web Vitals and real page speed. The length and count thresholds (title ~50–60 chars, description ~150–160, 300+ words, one H1) are approximations, not hard rules, and Google frequently rewrites titles and snippets. Your browser cannot fetch most live URLs (cross-origin / CORS) and there is deliberately no server proxy (so your page stays private), so the reliable path is to paste your page source. For a full multi-page crawl, rendered analysis and performance data, pair it with a dedicated crawler and Google’s own tools.

On-page guidance only — cannot see backlinks, domain authority or other off-page signals
Sees the HTML as pasted — no JavaScript rendering, no Core Web Vitals, no real page-speed measurement
Length / count thresholds are approximations; Google often rewrites titles and snippets per query
No server proxy — most live URLs are CORS-blocked, so paste your source (which keeps your page private)
For a full crawl and performance data, use Screaming Frog, Google Search Console and PageSpeed Insights

On-Page SEO Analyzer vs typical online SEO checkers
Capability	AnyTool On-Page SEO Analyzer	Typical online SEO checker
Processing	Runs entirely in your browser	Sends your page / URL to a server
Your page	HTML never uploaded, works offline	Page or URL crawled server-side
Staging / unreleased pages	Safe — nothing leaves the device	Exposed to a third-party service
Scope	Full page: title, meta, headings, images, links, content, technical	Sometimes meta-only or a URL crawl
Score	Weighted 0–100 score + letter grade + prioritized fixes	Varies; sometimes no score
Target keyword	Checked in title, H1, first paragraph, meta desc, URL + density	Often absent or basic
Fixes	A concrete fix per check	Sometimes vague or upsold
Honesty	Guidance — can’t see off-page / rendering / CWV	Often implies an authoritative verdict
Cost / signup	Free, no signup	Often gated or ad-heavy

AnyTool audits a page’s on-page factors locally from pasted HTML and uploads nothing, which is safe for staging or unreleased pages. It checks common best practices (length and count thresholds are approximations; Google rewrites titles / snippets), covers on-page factors only (not backlinks, rendering or Core Web Vitals), and is guidance rather than a ranking guarantee — for a full crawl and performance data use Screaming Frog, Google Search Console and PageSpeed Insights. Comparison as of July 2026.

Cite This Page

Title: On-Page SEO Analyzer (paste a page’s HTML source to run a full on-page SEO audit — title and meta description length, exactly one H1 with a logical H2–H6 outline, image alt text, internal vs external links, content length, canonical, robots/noindex, viewport, html lang, charset and JSON-LD structured data, plus an optional target-keyword usage check — with pass / warn / fail checks and a fix for each, grouped into Titles & Meta / Content & Headings / Images / Links / Technical, a weighted 0–100 score and a prioritized fix list, 100% client-side)
Author: AnyTool
Published: January 1, 2026
Modified: February 8, 2026
Section: SEO & Web
URL: https://www.anytool.tech/on-page-seo

Formatted Citation

AnyTool. "On-Page SEO Analyzer (paste a page’s HTML source to run a full on-page SEO audit — title and meta description length, exactly one H1 with a logical H2–H6 outline, image alt text, internal vs external links, content length, canonical, robots/noindex, viewport, html lang, charset and JSON-LD structured data, plus an optional target-keyword usage check — with pass / warn / fail checks and a fix for each, grouped into Titles & Meta / Content & Headings / Images / Links / Technical, a weighted 0–100 score and a prioritized fix list, 100% client-side)." AnyTool, January 1, 2026. https://www.anytool.tech/on-page-seo

A privacy-first, 100% client-side On-Page SEO Analyzer that runs a full on-page SEO audit of a single page from its pasted HTML source, entirely in the browser, with no server call, no CDN, no upload and no server proxy, so the page HTML pasted is never sent anywhere and the tool works offline once cached — making it safe to audit staging, unreleased or internal pages, unlike online SEO checkers that send your whole page or crawl your URL server-side. It is broader than a meta-tag analyzer: the user opens their page, copies its HTML source (View Source / Ctrl+U) and pastes it in, optionally adds a target keyword (an optional “try to fetch a URL” box exists but, with no server proxy, only works for CORS-enabled or same-origin pages — almost all live sites block cross-origin fetches, so the reliable path is pasting the source), and a small, pure, well-typed engine (onPageSeoEngine.ts, built on the browser’s DOMParser with a regex fallback so it never throws in a non-DOM environment, adding no dependency and reusing the project’s shared textStats() façade for the word count) audits the WHOLE page and returns a grouped report with an overall score. It extracts and grades the <title> (present, ~50–60 characters) and <meta name="description"> (present, ~150–160 characters); the heading structure, requiring exactly one <h1> stating the main topic and a logical H1→H6 outline with no skipped levels; every <img> and whether it has descriptive alt text (counting images missing alt, and noting intentionally-empty alt for decorative images); the links, classifying each <a href> as internal (relative / root-relative) or external (absolute) — excluding mailto:, tel:, javascript: and bare #fragment hrefs from the counts — and flagging nofollow, empty or image-only anchor text, and insecure http:// links; the body content length (word count and reading time from the shared engine, warning on thin sub-300-word pages); and the technical signals — the <link rel="canonical">, the <meta name="robots"> directive (flagging noindex prominently because the page would be excluded from search), the mobile <meta name="viewport"> (requiring width=device-width and warning when user-scalable=no disables pinch-zoom), the <html lang> attribute, the <meta charset> (preferring utf-8), and the presence of JSON-LD structured data and Open Graph / Twitter Card social tags. With an optional target keyword it checks whether the keyword appears in the title, H1, first paragraph, meta description and URL slug, and computes its body density, flagging BOTH absence (missing from the title or H1, its two strongest spots) and over-use (stuffing above ~4% density). Each check is a pass / warn / fail (or info) with the value found and a concrete one-line fix, grouped into Titles & Meta, Content & Headings, Images, Links and Technical; every scored check carries a weight reflecting how important the factor is, and the overall 0–100 SCORE is the weighted percentage of checks passed (a warning counts as half credit, a failure as zero), mapped to a letter grade A–F with a plain-language verdict, alongside a prioritized fix list that orders failures first and then by weight so the highest-impact work surfaces at the top, a page-stats panel (word count, heading outline, images and missing-alt, internal / external / nofollow links, and canonical / viewport / lang / JSON-LD presence) and a copyable plain-text report. It is deliberately HONEST about scope: it audits only the on-page factors present in the HTML you paste against widely-cited best practices, so it is guidance, not a ranking guarantee; it cannot see off-page factors (backlinks, domain authority, brand signals), how the page actually renders (JavaScript-injected content, layout), or your Core Web Vitals and real page speed; the length and count thresholds are approximations and Google frequently rewrites titles and snippets; and for a full multi-page crawl, rendered analysis and performance data it recommends a server-side crawler such as Screaming Frog together with Google Search Console and PageSpeed Insights, which this fast, private, single-page audit complements. It is a sibling to the Meta Tag Analyzer (meta tags only), the SERP Preview, the Structured Data Tester and the Website Link Extractor in the SEO & Web family, supports dark mode and mobile with a sticky Analyze / Copy bar, has exactly three ad slots, and adds no new dependency.

How do I run a full on-page SEO audit of a page &mdash; title, meta, headings, images, links, content and keyword usage &mdash; with a score, without uploading my HTML?