7 Best Free Online SEO Checkers Compared (2026)

An SEO checker is any tool that analyses a website and tells you how well it is optimised for search engines. In 2026, dozens of free options exist — but they vary wildly in what they actually check, how accurate the results are, and whether the output is actionable.

We compared the 7 best free online SEO checkers to help you find the right one for your specific situation.

What Should a Good SEO Checker Do?

A quality SEO checker should cover at minimum:

• On-page elements: title tags, meta descriptions, headings, image alt text
• Technical health: page speed, mobile-friendliness, HTTPS, crawlability
• Content quality: readability, keyword usage, duplicate content signals
• Backlink overview: link count, referring domains, spam indicators
• Actionable recommendations — not just a list of problems

The best tools in 2026 go further by adding competitive context and AI-generated interpretation.

1. BenchSpy — Best for Competitor SEO Checking

BenchSpy stands out among SEO checkers because it checks ANY URL — including your competitors' — and returns an AI-written analysis rather than a raw checklist. Paste a competitor's URL and within 60 seconds you get: SEO audit scores, PageSpeed grades, tech stack, positioning analysis and a full SWOT report.

The free tier includes 3 complete analyses with no credit card required. For ongoing checking of multiple sites, the Starter plan is €9/month.

What it checks: On-page SEO, PageSpeed, Core Web Vitals, tech stack, positioning, competitive SWOT
Free limit: 3 full analyses
Unique advantage: AI-written intelligence, not just a score

2. Google PageSpeed Insights

Google's own free tool checks any URL for performance and Core Web Vitals using both Lighthouse lab data and real Chrome User Experience data. It is the definitive source for performance scoring — all other tools reference Google's metrics.

What it checks: Performance, Core Web Vitals (LCP, INP, CLS), Lighthouse scores
Free limit: Unlimited
Unique advantage: Official Google data, real user field data included

3. SEOptimer Free

SEOptimer runs a quick website audit grading your page on SEO, performance, social, usability and security — producing a letter grade and actionable recommendations for each category. The interface is clean and the free one-off check covers most basics without requiring an account.

What it checks: On-page SEO, performance, social tags, security, usability
Free limit: Unlimited single-URL checks (monitoring requires paid plan)
Unique advantage: Clean presentation, good for sharing with clients

4. HubSpot Website Grader

HubSpot's Website Grader produces an overall score and sub-scores for performance, SEO, mobile and security. It runs in seconds, requires no account and works on any URL. The recommendations are beginner-friendly — ideal if you are explaining SEO basics to a client or stakeholder.

What it checks: Performance, SEO basics, mobile-friendliness, security headers
Free limit: Unlimited one-off checks
Unique advantage: Accessible language, good for client education

5. Ahrefs Free SEO Checker

Ahrefs offers a free on-page SEO report for any URL — checking title tags, meta descriptions, headings, image alt text and canonicals alongside basic performance data. The data quality is high given Ahrefs' reputation, though the free version is limited compared to their paid plans.

What it checks: On-page SEO elements, basic performance, some backlink data
Free limit: Limited daily checks without account
Unique advantage: Ahrefs-quality data, detailed on-page breakdown

6. SEO Site Checkup

SEO Site Checkup runs over 30 SEO tests on any URL and displays results in a clean checklist format — covering meta tags, headings, mobile friendliness, page speed, social tags, backlinks and more. The free tier gives you a complete report; the paid plan adds monitoring and tracking.

What it checks: 30+ SEO checks across on-page, technical and social
Free limit: Unlimited one-off checks
Unique advantage: Comprehensive checklist, good breadth of checks

7. Sitechecker Free

Sitechecker's free tier provides a single-page SEO audit covering on-page elements, technical issues and basic performance. The interface is visual and easy to understand — useful for quick health checks and initial site assessments.

What it checks: On-page SEO, meta tags, performance basics, mobile check
Free limit: Limited free crawl
Unique advantage: Visual report format, beginner-friendly

Comparison Table

Which Free SEO Checker Should You Use?

For most users, the ideal free SEO checking stack in 2026 is:

• Performance: Google PageSpeed Insights (unlimited, official data)
• On-page SEO: SEOptimer or Ahrefs free checker
• Competitor intelligence: BenchSpy free tier (3 full AI-powered analyses)

This combination covers your own technical health and — crucially — gives you strategic intelligence on competitors that basic audit tools cannot provide. Try BenchSpy free to see how your competitors' SEO stacks up.