The free SEO toolkit trusted by 1,000s of developers, SEO pros & agencies

The best free SEO tools, no sign-up required.

RankNibbler is the browser-based SEO toolkit thousands of developers, SEO pros, and agencies use every week to audit websites — without paying $99/month or handing over an email. 30+ tools, instant results, free PDF & CSV export. No account, no upsell, no limits.

30+ tools • 10,000+ audits daily • 0 accounts required
2026 AI Overview optimisation built-in Speakable schema sitewide Chrome DevTools-style trace view Free PDF & CSV export

Developers

Ship clean SEO alongside your code. Every tool runs in your browser with zero install, zero tracking, and a keyboard-friendly UI that stays out of your way.

SEO consultants

Audit unlimited client sites, export white-labelled PDF reports, and pull CSVs for your dashboards — without burning through Ahrefs or SEMrush seats.

Agencies

Run on-page audits and full sitemap crawls (up to 1,000 URLs) on every client site. No per-seat pricing, no audit limits, no quarterly renewals.

In-house marketers

Spot SEO issues before they hit production. Heading structure, schema validation, Core Web Vitals, AI Overview readiness — all in one tab.

On-page audit & analysis

6 tools
Flagship

SEO Checker

The main RankNibbler tool. Enter any URL, get a score out of 100 based on 30+ on-page checks — title tags, meta, headings, schema, alt text, readability, tech stack, accessibility, and more. PDF & CSV export.

Open tool → Crawler

Site Audit

Enter a domain and RankNibbler crawls your sitemap.xml, discovers every page, then audits up to 1,000 pages automatically. Find your weakest URLs in minutes.

Open tool → Bulk

Bulk URL Checker

Paste up to 20 URLs and get SEO scores for all of them at once. Each result has expandable details. Perfect for auditing a section or comparing competitor pages. CSV export.

Open tool → Compare

SEO Compare

Enter two URLs and an optional target keyword to see side-by-side comparison of every on-page factor. Find out exactly where your competitor outranks you.

Open tool → Rankings

Keyword Rank Checker

Check your Google ranking position for any keyword and any URL. Useful for monitoring SERP position changes on the fly.

Open tool → Score

SEO Score Checker

Understand how the RankNibbler score is calculated. Points per check, thresholds, and what "good" looks like.

Learn more →

Link tools

5 tools
Broken links

Broken Link Checker

Scan any page for dead links, 404 errors, and redirect chains. Checks up to 100 links per page with filters and CSV export.

Open tool → Redirects

Redirect Checker

Check HTTP/HTTPS and WWW/non-WWW variants all redirect to the same canonical URL. Detects chains and temporary redirects.

Open tool → Analysis

Link Analysis

Count internal vs external links, see anchor text, rel attributes, and nofollow ratios for any page.

Learn more → Nofollow

Nofollow Checker

Identify which links use rel="nofollow" and what percentage of your links are nofollowed.

Learn more → Empty links

Empty Links Checker

Detect links with no text or aria-label — a common accessibility and SEO issue.

Learn more →

Meta & content tools

7 tools
SERP preview

SERP Snippet Generator

Preview how your page appears in Google search results. Pixel-width meters show exactly where Google will truncate your title and description.

Open tool → Generator

Meta Tag Generator

Generate title, description, Open Graph, and Twitter Card tags from a simple form. Copy-ready HTML output.

Open tool → Check

Title Tag Checker

Check any page's title tag presence, length, and how it'll display in search engines.

Learn more → Check

Meta Description Checker

Verify meta description length (120–160 chars) for search result snippets and preview.

Learn more → Readability

Readability Checker

Flesch–Kincaid grade level, sentence length, syllable complexity for any page's content.

Learn more → Keywords

Keyword Density Checker

Extract top 15 keywords and 2-word phrases from any page with frequency and density percentages.

Learn more → Word count

Word Count Checker

Count words on any URL. Flags thin content below 300 words. Shows text-to-HTML ratio.

Learn more →

Structured data & social

4 tools
Generator

Schema Markup Generator

Create JSON-LD for FAQ, Article, Product, LocalBusiness, Event, and Recipe schema types. Copy-paste output.

Open tool → Detect

Structured Data Checker

Detect JSON-LD Schema.org markup on any page. Validates required fields for 15+ schema types.

Learn more → OG tags

Open Graph Checker

Check Open Graph and Twitter Card tags so your links preview correctly on Facebook, LinkedIn, Slack, and X.

Learn more → Preview

Open Graph Preview

See how your links will appear when shared on Facebook, Twitter/X, LinkedIn, and Discord.

Open tool →

Technical SEO

6 tools
Generator

Robots.txt Generator

Generate a valid robots.txt file with allow/disallow rules, sitemap reference, crawl-delay, and user-agent directives.

Open tool → Generator

.htaccess Redirect Generator

Create 301 redirect rules for Apache. Supports single redirects, HTTPS enforcement, and WWW canonicalisation.

Open tool → Extract

Heading Outline Extractor

Extract the H1–H6 tree from any webpage. Visualise heading hierarchy and find skipped levels.

Open tool → Minifier

HTML Minifier

Minify HTML code to reduce file size. Removes comments, whitespace, and unnecessary attributes.

Open tool → Speed

Page Weight & Performance

Measure total page weight, number of requests, and get a full Core Web Vitals report via Google PageSpeed.

Open tool → Detect

Tech Stack Checker

Detect CMS, frameworks, analytics, CDNs, and 40+ technologies from the HTML source of any public URL.

Learn more →

Technical checkers

5 tools
Security

HTTPS & URL Checker

Verify HTTPS is enabled, URL structure is clean, and there are no obvious technical issues.

Learn more → Canonical

Canonical URL Checker

Verify the canonical tag is set correctly to prevent duplicate content indexing issues.

Learn more → Directives

Robots Directives Checker

Detect noindex, nofollow, and crawl-blocking meta tags that could hide your content from Google.

Learn more → Images

Image Alt Text Checker

Find every image on a page missing alt text. Critical for accessibility and image SEO.

Learn more → Accessibility

Accessibility Checker

Basic WCAG checks: form labels, skip nav, ARIA landmarks, linked-image alt text.

Learn more →
Why free

Why every tool is free

RankNibbler was built as a practical utility, not a SaaS business. Here's how we keep it free forever.

Runs in your browser

Tools analyse pages client-side. We don't store your audit results, page content, or usage data. No accounts, no tracking tables, no database costs.

No premium tier

Every feature is available to every visitor. No feature gates, no limits on audit count, no paywalls on export. What you see is what you get.

Built for developers

Fast, keyboard-friendly, minimal JS, no tracking. If you want to ship clean SEO alongside your code, these tools stay out of your way.

Compare

RankNibbler vs. other SEO tools

How our free browser-based tools compare to the bigger paid suites for on-page SEO work.

Feature RankNibbler Ahrefs / SEMrush Screaming Frog Lighthouse
Price Free $99–$449/mo Free (500 URLs) / £199/yr Free
Account required No Yes Install required No
On-page audit (30+ checks) Yes Yes Yes Partial
Schema validation Yes (15+ types) Yes Yes No
Backlink analysis No Yes No No
Keyword rank tracking Spot-check Yes No No
Tech stack detection 40+ Partial Partial No
PDF / CSV export Yes Yes Yes HTML only
In-browser (no install) Yes Yes No DevTools only
FAQ

Frequently asked questions

Are RankNibbler's SEO tools really free?

Yes. Every tool on RankNibbler is completely free with no sign-up, no daily limits, and no premium tier. The tools run entirely in your browser, which is why we can keep them free forever.

Do I need to create an account to use these SEO tools?

No. You can use every tool without creating an account, providing an email, or paying anything. Just visit the tool, paste your URL or content, and run it.

How does RankNibbler compare to paid SEO tools like Ahrefs, SEMrush, or Screaming Frog?

RankNibbler focuses on on-page and technical SEO audits — title tags, meta descriptions, heading structure, schema, accessibility, page weight. Ahrefs and SEMrush focus on backlinks and keyword data, which we don't cover. Screaming Frog is a desktop crawler with bulk-crawl capability but requires installation and licensing for larger sites. RankNibbler covers most on-page needs free, in-browser. For backlinks or bulk crawls, you'll want a paid tool in addition.

Can I use these tools for client SEO audits?

Yes. Every audit can be exported as a branded PDF or CSV for client reports. The tools have no usage limits so you can audit as many client sites as you need. White-label not available (the RankNibbler name appears in reports).

Do the tools work for any website platform?

Yes. RankNibbler tools work with any publicly accessible webpage — WordPress, Shopify, Wix, Squarespace, BigCommerce, Magento, headless setups, and custom-built sites. They fetch the HTML the same way a search engine crawler would. For password-protected staging sites, use the HTTP Basic auth fields on the homepage audit tool.

What about Core Web Vitals and page speed?

The Page Weight & Performance tool connects to Google's PageSpeed Insights API to return the full Core Web Vitals report (LCP, CLS, INP) for any URL. You can also see total page weight and request counts from the main audit.

Do you have a command-line or API version?

Not yet. RankNibbler is currently browser-only. If there's demand for a CLI or programmatic API, we'll build one. Get in touch via GitHub if you need it.

How often are the tools updated?

We update check criteria whenever Google announces new ranking factors or deprecates old ones. The tools have been updated multiple times in 2026 to cover AI Overviews optimisation, Core Web Vitals INP metric, and expanded schema validation.

Start with a single audit.

Paste a URL, get a full SEO score in under a second. No sign-up.

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