Detailed SEO Extension: The Free Chrome Tool We Use for Quick SEO Audits (Full Guide)

Whenever we’re auditing a client’s website or checking a competitor’s page structure, this is the extension we reach for first. The Detailed SEO Extension is a free Chrome and Firefox tool built by SEO Glen Allsopp, used by over 450,000 people to pull page-level SEO data in a single click — no need to dig through source code.

This guide covers exactly what it does, how to install it, and how to actually use each feature. Bookmark this page — it’s the one we’ll keep pointing people to whenever they ask for the tool link.

What Is the Detailed SEO Extension?

It’s a free browser extension that shows you the technical and on-page SEO details of any page you’re currently viewing — headings, meta tags, schema markup, links, images, and more — without opening a separate tool or viewing page source manually. It’s completely free, with no upsells, no paid tier, and no tracking.

Get the Extension

• Chrome: Add Detailed SEO Extension to Chrome
• Firefox: Add Detailed SEO Extension to Firefox

Official tool page: detailed.com/extension

Key Features and How to Use Them

1. Quick Page Overview

Click the extension icon on any page and it instantly surfaces the key on-page elements — title tag, meta description, canonical tag, and even X-Robots HTTP headers — without you needing to view source code.

2. Heading Structure at a Glance

The Headings tab lists every H1 through H6 on the page, indented to show hierarchy, with font sizes scaled to match. This makes it easy to instantly spot whether a page is under-optimised, over-optimised, or structured properly for both readers and search engines.

3. Supercharged Right-Click Menu

Right-click anywhere on a page to instantly open that URL (or domain) in Ahrefs, Moz, Majestic, Archive.org, SimilarWeb, SEMrush, and more — saving you from manually copying URLs into each tool separately.

4. View Schema Markup Without a Separate Tool

The Schema tab shows any structured data markup used on the page you’re viewing, so you can check FAQ schema, review schema, or product schema instantly instead of running it through a validator tool first.

5. Find Duplicate Content on the Web

Highlight any text on a page and the extension can search the web for duplicates — useful for checking if a competitor copied your content, or whether a freelance writer lifted a paragraph from elsewhere.

Other Features Worth Knowing

• Extract “People Also Asked” questions directly from Google search results in one click (enable this under the Advanced tab) — a genuinely useful shortcut for content and FAQ ideas.
• Change your user agent to view a site the way Googlebot sees it.
• Hreflang quick view to check all localised versions of a page at once.
• One-click access to any site’s sitemap.xml from the overview tab.
• Export all page links or image URLs as a CSV file for further analysis.
• Highlight nofollow links directly on the page.
• One-click site:domain searches from the right-click menu.

Why We Use This for Client SEO Audits

Most of what this extension shows you, you could technically find by digging through page source or running separate tools. What makes it worth installing is speed — when you’re auditing dozens of pages across a client site, checking heading structure and schema in one click instead of five saves real time. It’s part of the same technical-SEO groundwork we cover when doing SEO audits for clients, and it pairs well with the kind of AI-search readiness checks we outlined in our guide on what is llms.txt and how AI SEO works.