CheckSEO

Full-Site Overviews On-Page SEO Technical SEO Domain & Network Structured Data Social Sharing Developer Utilities YouTube Tools All 84 tools

Free SEO tools — meta tags, headings, images, keywords, and a full site audit. No signup.

Free SEO tools to check, audit, and fix your website

CheckSEO is a collection of 84 free tools for website owners, developers, marketers, and YouTube creators. Paste a URL and see exactly what search engines see: your title and meta tags, heading structure, image alt text, canonical and hreflang tags, redirects, robots.txt, sitemap, Core Web Vitals, structured data, and security headers. Every check explains what it found, why it matters, and how to fix it.

There is no signup and no paywall on any tool. The Full Site Audit runs the on-page and technical checks together and gives you one score to start from; the individual tools let you dig into a single issue. Alongside the tools, the blog has in-depth guides written by the developer who built them.

Run the free Full Audit See a sample site report (PDF)

Where to start

A full audit is a good first step; anything it flags can then be checked on its own with a single-page tool. The checks work from what is publicly visible, the way a crawler does, so there is nothing to install and no access to your site to grant. Four tools to try first:

Full Site Audit runs the on-page and technical checks together. The core checks show straight away; add your email only if you want the advanced checks unlocked and a free One-Page Report sent to you.
Meta Tag Checker reads a page's title tag, meta description, canonical link, Open Graph and Twitter Card tags, checks title and description length, and shows the fix for each problem.
Schema Markup Validator finds every JSON-LD block in a page's HTML and checks that it parses and declares a type.
YouTube Channel Statistics shows subscribers, total views, video count, join date and country for any public channel, with no API key or login.

When one page is not enough, the Full Site Report audits every page of your site, up to 100 pages on the Standard plan or 1,000 on the Full plan, and emails you a ready-to-paste fix for each page within 24 hours. It is paid, and separate from the free tools.

If you would rather understand a result before acting on it, the CheckSEO blog has step-by-step guides, each paired with the tool that tests the fix on your own site.

Browse tools by category

Full-Site Overviews

Run every check at once and get one score to start from.

6 tools

On-Page SEO

Title tags, headings, images, and content — what search engines read first.

10 tools

Technical SEO

Redirects, sitemaps, and crawl rules — the plumbing search engines depend on.

17 tools

Domain & Network

DNS, certificates, headers, and registration — what's true about a domain before any page loads.

7 tools

Structured Data

Generate the JSON-LD markup search engines use for rich results.

8 tools

Social Sharing

How your links actually look when they're shared.

5 tools

Developer Utilities

General-purpose tools that don't need a URL at all.

15 tools

YouTube Tools

For creators — no API key, no login.

16 tools

Popular free SEO tools

Meta Tag Checker

Check title, description, canonical, Open Graph, and Twitter Card tags.

H1 Checker

Check a page's H1 and its full H1–H6 heading structure.

Alt Text Checker

Find images missing alt text across a page.

Duplicate Content Checker

Compare two URLs and see how much of their visible text actually overlaps.

Anchor Text Analyzer

Extract every link's anchor text on a page and flag generic, non-descriptive links like "click here".

Blacklist / Spam Checker

Check a domain's IP against public DNS blacklists used for spam and reputation filtering.

Mobile-Friendly Test

Test whether a page is mobile-friendly: viewport tag, zoom, legacy tech and text size. A free replacement for Google's retired Mobile-Friendly Test.

Full Site Audit

Run every on-page and technical SEO check against a URL in one pass.

More checks worth running

Broken Link Checker

Scan a page's links and find the ones that return 404s, errors, or time out.

SERP Snippet Preview

See exactly how a title and meta description will look in Google results before you publish.

Core Web Vitals Checker

Run a real Lighthouse check and see actual LCP, CLS, and INP — lab data plus real-world Chrome UX Report field data, when available.

Email Deliverability Checker

Check a domain's SPF, DKIM, and DMARC setup and see exactly what's missing or misconfigured.

Keyword Suggestion Tool

Get the real phrases people type into Google for any seed keyword, pulled from autocomplete.

Domain Age Checker

Find out when a domain was first registered, when it expires, and who the registrar is.

Schema Markup Validator

Find every JSON-LD block on a page and check that each one parses and has a @type.

Schema Markup Generator

Build JSON-LD for Article, Product, LocalBusiness, Organization, Event, Video, HowTo, and Breadcrumb.

YouTube tools for creators

All YouTube tools

Look up any public channel or video, write titles, tags, descriptions and hashtags, and grab thumbnails, logos and banners. No API key and no login — it works from public data only.