Free SEO Tools That Run in Your Browser
30 free tools — Paste-based SEO analyzers — meta tags, SERP preview, schema, readability
Keyword Density Checker
Paste your content to see word and phrase frequency. Counts 1-, 2- and 3-word terms with a density percentage so you can spot over-optimization.
Meta Tag Analyzer
Paste a page's HTML source to extract and grade its title, description, robots, canonical, Open Graph and Twitter tags with length and best-practice warnings.
Google SERP Preview
Type a title, description and URL to see a live Google desktop and mobile snippet, with pixel-width truncation that matches how search results actually display.
Schema Markup Validator
Paste JSON-LD structured data to validate its JSON syntax and confirm the required schema.org properties for the detected @type are present.
Title Tag Length Checker
Type a page title to see its character count and estimated pixel width, with a preview showing where Google truncates it on desktop and mobile.
Anchor Text Extractor
Paste HTML to list every link with its anchor text, href, rel attribute and an internal-versus-external flag so you can audit your internal linking.
Heading Structure Checker
Paste HTML to see an indented outline of every H1-H6 heading, with warnings for multiple H1s, skipped levels and empty headings.
Open Graph Checker
Paste HTML to extract its Open Graph tags, preview the link card and get warnings for missing required properties like og:title, og:image and og:url.
Twitter Card Checker
Paste HTML to extract Twitter Card tags, preview the card and validate the card type plus required twitter:title and twitter:image properties.
Canonical Tag Checker
Paste HTML to find its canonical link tag and flag common problems: missing tag, multiple canonicals, relative URLs or self-referencing mismatches.
Hreflang Tag Generator
Enter a URL and language-region pairs to generate valid rel=alternate hreflang link tags, with ISO 639-1 and ISO 3166-1 code validation.
Disavow File Generator
Paste a list of spammy domains or URLs to build a properly formatted Google disavow file, automatically adding the domain: prefix where appropriate.
Structured Data Tester
Paste JSON-LD to detect every schema.org type, see all properties in a readable tree and check required and recommended fields for rich-result eligibility.
Readability Score Checker
Paste text to compute its Flesch Reading Ease, Flesch-Kincaid grade level, average sentence length and percentage of complex words.
HTTP Header Checker
Enter a URL to see the live HTTP response status and every header the server returns, including caching, security and content-type directives.
Redirect Checker
Trace the full redirect chain for a URL, hop by hop, with the status code and Location header at each step so you can spot 302s, loops and long chains.
Broken Link Checker
Enter a page URL and we extract its outbound links and test each one, reporting the status code so you can fix 404s and dead references.
Robots.txt Tester
Fetch a site's robots.txt, show its raw rules, count the user-agent groups and list every sitemap it declares.
XML Sitemap Validator
Fetch an XML sitemap and check its structure, detect whether it is a urlset or sitemapindex, count the URLs and surface formatting errors.
Google Index Checker
Build an accurate site: operator query for a URL and open it on Google and Bing to see whether the page appears in the search index.
DNS Lookup
Look up A, AAAA, MX, TXT, NS and CNAME records for any domain using DNS over HTTPS, returned from our server in one query.
SSL Certificate Checker
Connect to a domain over TLS and read its certificate issuer, subject, validity dates, days remaining, SAN list and negotiated protocol.
IP Address Lookup
Enter an IP address to see its approximate country, region, city, ISP, organisation, autonomous system, coordinates and timezone.
Page Speed Test
Enter a URL to measure its Lighthouse performance score plus First Contentful Paint, Largest Contentful Paint, Total Blocking Time and Cumulative Layout Shift on mobile or desktop.
Core Web Vitals Check
Enter a URL to read its Core Web Vitals — LCP, INP and CLS — alongside FCP, Total Blocking Time and Speed Index from Lighthouse for mobile or desktop.
WHOIS Lookup
Enter a domain to retrieve its WHOIS record — registrar, creation, update and expiry dates, name servers and registration status.
Domain Age Checker
Enter a domain to see when it was first registered, how many years old it is, and when its current registration expires.
Backlink Checker
Enter a domain to see its total backlinks, the number of unique referring domains and referring IPs, and an overall link rank score.
Domain Authority Check
Enter a domain to retrieve its rank score — a 0-1000 measure of overall link strength that estimates how competitive the domain is in search.
Keyword Suggestions
Enter a seed keyword to get related search terms with their estimated monthly search volume and a competition score, ready to sort and scan.
About SEO Tools
These SEO tools analyze content you paste, not URLs you enter. Because browsers block cross-origin requests, a 100% client-side tool can't fetch another site's HTML — so every tool here works on text, HTML source, or JSON-LD you copy in. That keeps everything private (nothing is uploaded) and lets you audit staging pages, gated content, and competitor source alike.
The set covers on-page essentials: keyword density (1/2/3-gram), a meta tag analyzer that grades title/description/robots/canonical/social tags, a pixel-accurate Google SERP preview, title-length checker, anchor-text extractor, heading-structure outline, Open Graph and Twitter Card checkers, a canonical validator, an hreflang generator with ISO code validation, a Google disavow file builder, JSON-LD structured-data testers, and a Flesch readability scorer.
These are paste-based analyzers and generators, not crawlers or rank trackers — they never call an external API. URL-fetch tools (robots/sitemap/page-speed/headers/redirects/backlinks) require a server and are a later round.