Free on-page SEO tool

HTML SEO Analyzer

Paste a page's HTML and audit the on-page SEO signals that are easy to miss: metadata, keyword alignment, headings, links, image alt text, indexability and JSON-LD structured data.

View every check Source-level analysis · Runs locally in your browser

Paste source HTML

Analyze the page before you publish.

Runs in your browser

HTML SEO audit coverage

What does the HTML SEO Analyzer check?

SERPbeam audits the HTML source you paste and explains what it finds, why a finding matters and, where possible, the exact element responsible. The analyzer focuses on on-page SEO checks that can be verified reliably from source HTML rather than pretending to validate signals it cannot see.

01

Search metadata and indexability checks

Review the source-level tags that influence how a page can be indexed, consolidated and presented in search results.

The analyzer extracts the page title, meta description, canonical URL and robots meta directives directly from the HTML. It does more than confirm that a tag exists: it evaluates useful writing ranges, shows the current value from the page and explains canonical relationships when a Page URL is supplied.

  • Title tag: checks presence and character length, then shows the exact title found in the source.
  • Meta description: checks presence and length and clearly separates the page's existing description from SERPbeam's assessment.
  • Canonical URL: detects the canonical and identifies whether it is self-referencing, points to another URL on the same site, or points to a different host.
  • Robots meta: detects page-level robots directives and flags noindex when present.
  • Indexability context: reports when no page-level noindex directive is found without claiming that the page is fully crawlable or indexable from HTML alone.
02

Keyword and content alignment checks

Use an optional primary keyword or target query to review whether important on-page elements support the topic of the page.

SERPbeam uses lightweight phrase and term overlap rather than a keyword-density formula. The aim is to spot obvious misalignment between the target query and the page's core elements without encouraging exact-match repetition or keyword stuffing.

  • Title and H1 alignment: checks whether the title tag and primary H1 support the supplied target query.
  • Meta description relevance: reports whether the target-query terms appear in the description.
  • Visible-copy relevance: checks whether the page body contains language related to the supplied target query.
  • Visible word count: estimates words from visible body text while excluding scripts, styles, templates and similar non-content elements.
  • Content-length review: uses a review threshold as a prompt for editorial judgement, not as a Google ranking rule or universal minimum word count.
03

H1, H2 and heading structure checks

Inspect the document outline and identify exactly where heading hierarchy becomes inconsistent.

A heading audit should show the structure, not merely count tags. SERPbeam builds the H1-H6 outline, checks the H1 situation and points to the precise headings involved when a level is skipped.

  • H1 count: checks whether the source contains zero, one or multiple H1 headings and shows the current H1 value when there is one.
  • Full document outline: lists H1 through H6 headings in source order so the page hierarchy can be reviewed visually.
  • Skipped heading levels: detects jumps such as H2 → H4.
  • Exact affected headings: shows both headings involved in each hierarchy jump instead of returning a vague warning.
  • Empty headings: identifies heading elements that contain no meaningful text.
05

Image alt text and accessibility checks

Review whether images have usable alternative text while avoiding simplistic advice to force keywords into every image.

The image audit checks alt attributes at both summary and element level. When an issue is detected, SERPbeam identifies the affected image source so the problem can be found quickly in the HTML.

  • Missing alt attributes: finds images where the alt attribute is absent.
  • Empty alt values: reports empty alt text separately because alt="" can be correct for purely decorative images.
  • Long alt text: flags alt values over the analyzer's 125-character review threshold.
  • Generic or file-name alt text: identifies values such as “image”, “photo” or image-file names that may not describe the visual meaningfully.
  • Duplicate alt text: surfaces repeated non-empty alt values for editorial review.
  • Target-query context: checks whether an image's alt text or nearby visible copy relates to the supplied target query, while explicitly avoiding a recommendation to repeat the keyword in every alt attribute.
06

JSON-LD and schema markup checks

Inspect structured data beyond a simple “schema found” message by showing detected entities, values, search treatment and relevant opportunities.

SERPbeam parses JSON-LD blocks and separates three different questions: whether the JSON syntax is valid, what schema.org markup is present, and how the schema type relates to current Google Search features. A schema type can remain semantically useful even when a Google rich result has been deprecated.

  • JSON-LD syntax: identifies parseable and invalid application/ld+json blocks.
  • Detected schema types: lists schema entities found in normal JSON-LD arrays and @graph structures.
  • Schema property values: exposes properties and values from the markup so users can inspect what the page is actually declaring.
  • Google Search treatment: distinguishes currently supported structured-data features, semantic/unmapped schema and deprecated rich-result types.
  • HowTo and FAQPage nuance: explains that deprecated Google rich results do not automatically make accurate semantic markup bad practice.
  • Schema opportunities: conservatively looks for visible signals that may justify BreadcrumbList, Article, VideoObject, FAQPage or HowTo markup when those types are not already present.
  • No fake validation: SERPbeam does not label markup “Google-valid” merely because the JSON parses; full eligibility still depends on schema-specific requirements and search-engine guidelines.