SEO Checker — Free Audit Metadata, Preview SERP Snippets, Validate Schema

Most SEO QA happens across five or six separate tools: a snippet preview tool for checking title length, an Open Graph tester for social cards, a JSON-LD validator for schema, a robots meta checker for crawlability, and a manual checklist for everything else. Switching between them on every page is slow, easy to skip, and misses the connections between issues — a canonical that conflicts with the og:url will silently affect both crawlability and social sharing, but you'd only catch it if you happened to check both at the same time. The SEO Checker replaces that fragmented workflow with a single browser-based audit that runs every check together and rolls them into one 0–100 score.

Enter any public URL or paste your page HTML. The tool extracts every SEO-relevant signal from the document — title tag, meta description, robots directives, canonical URL, Open Graph fields, Twitter card tags, JSON-LD structured data, H1 and heading outline, body word count, internal and external links, image alt text, and image attributes — and surfaces them in a scored dashboard across seven audit categories.

Metadata covers the fundamentals that affect every page: title tag (length, keyword placement), meta description (length, presence), robots meta directive (index/noindex, follow/nofollow), and canonical URL format. The audit flags titles that are too short to be meaningful or too long to display fully in Google results, descriptions that are missing or duplicate the title, and canonical URLs that point to HTTP instead of HTTPS.

Crawlability is where silent indexing mistakes hide. A page with noindex in its robots meta tag will never appear in Google results — but it looks completely normal in a browser. A canonical URL with a query string (?ref=newsletter) can confuse Googlebot about which URL is authoritative. A canonical pointing to a different subdomain than the og:url tells Google and social platforms different things about the same page. The Crawlability panel catches all of these before they go live.

Content checks word count (thin content below 300 words is a common quality signal issue), H1 presence and alignment with the title tag (Google uses both to understand the page topic), heading outline logic (skipping from H1 to H3 confuses document structure), and the first paragraph (keyword in the opening sentence is a strong on-page signal).

Social renders card previews for all four platforms where link sharing matters. Facebook and LinkedIn both read Open Graph tags — og:title, og:description, og:image — and will show a blank gray card if the image is missing or returns a 4xx error. X/Twitter reads twitter:card, twitter:title, and twitter:image. Slack reads og:image and og:title for link unfurling in channels. The Social tab shows all four previews side by side so you can catch truncation and missing images across every platform at once.

Schema parses any JSON-LD already on the page and displays the detected type and key fields. The built-in Schema Builder generates clean JSON-LD for the eight most common schema types: WebPage, Article, BlogPosting, Product, FAQPage, SoftwareApplication, LocalBusiness, and BreadcrumbList. Structured data is increasingly important for rich results in Google Search — an Article schema enables the article rich snippet, a FAQPage schema can trigger expandable Q&A entries in results, and a Product schema enables price and availability badges.

Links and Images cover accessibility and SEO signals that are easy to miss at scale. The Links audit checks for empty anchor text, overly generic text like "click here" or "read more", the ratio of internal to external links, and links with missing or broken hrefs. The Images audit checks alt text coverage (empty alt text on non-decorative images is both an accessibility failure and a missed keyword opportunity), missing width and height attributes (which cause layout shift that hurts Core Web Vitals), and missing loading="lazy" on below-the-fold images.

The Output tab exports implementation-ready code the moment you have the metadata right. Switch between HTML tags (paste into any <head>), Next.js export const metadata object, React Helmet JSX, Astro head component, and JSON-LD. The Report tab packages the full audit into a Markdown file you can paste into a GitHub issue, Notion page, or client report — or a JSON file for programmatic integration with CI pipelines or audit dashboards. Pair the auditor with the meta tag generator to build tags from scratch, the schema markup generator for structured data, and the sitemap generator for clean indexing.