Every major free SEO browser extension ranked by actual free value — no account requirements, no paywalls. Based on features you get without spending a penny.
| Rank | Extension | Best free feature | Account needed? | Chrome | Firefox |
|---|---|---|---|---|---|
| 🥇 1 | Ahrefs Toolbar | On-page audit + redirect tracer | No | ✓ | ✓ |
| 🥈 2 | SEOquake | Full SERP overlay + CSV export | No | ✓ | ✓ |
| 🥉 3 | Keyword Surfer | Search volumes in Google results | No | ✓ | ✗ |
| 4 | MozBar | DA/PA on every page | Free account | ✓ | ✓ |
| 5 | SEO Minion | Hreflang checker | No | ✓ | ✗ |
| 6 | Wappalyzer | Tech stack detection | No | ✓ | ✓ |
| 7 | Semrush Toolbar | Limited without account | Semrush plan | ✓ | ✗ |
You don't need to choose just one. The optimal free combination for 2026:
Core stack (always on): Ahrefs Toolbar + Keyword Surfer. Ahrefs handles all technical and on-page analysis; Keyword Surfer adds search volumes to Google results.
Add when doing SERP research: Toggle SEOquake on. Full authority overlay, traffic estimates, and CSV export — disable it between research sessions to reduce clutter.
Add for link building: MozBar. DA/PA visible on prospects without switching tools. Enable only during outreach/prospecting sessions.
Total cost: £0. Combined coverage: on-page audits, redirect tracing, SERP authority analysis, search volumes, DA/PA, CSV export, hreflang validation, and tech stack detection.
Start with Ahrefs SEO Toolbar. It provides the widest range of free technical SEO capabilities without any account, works across Chrome, Firefox, and Safari, and is the foundation of any professional SEO extension stack. Then add Keyword Surfer for instant search volume context in Google results.