The best SEO plugins for Firefox let you analyse pages, check backlink metrics, research keywords, and run technical audits without leaving your browser or switching between tools. Firefox has a smaller extension library than Chrome but every tool that matters is available — and several are entirely free with no account required.
This guide covers ten of the most useful Firefox SEO extensions currently available, what each one does well, where it falls short, and which combination makes sense for your specific workflow. Running too many simultaneously slows Firefox and clutters your toolbar — the goal is a lean, purposeful stack rather than installing everything at once.
1. Detailed SEO Extension
Detailed SEO Extension is the best free on-page SEO plugin for Firefox right now. It stepped in as the top free pick after SEO Minion moved to a paid subscription model, and it handles everything SEO Minion used to do at no cost. One click surfaces every critical on-page element — title tag and meta description with character counts, full heading structure from H1 through H6, canonical URL, robots meta directives, structured data and schema markup detection, internal and external link counts with anchor text, image alt text coverage, and Open Graph and Twitter Card tags.
The strongest thing about Detailed is its speed and simplicity. There is no account to create, no dashboard to navigate, and no upsell pushing toward a paid tier. It is a tool that does one job extremely well. The limitation is scope — it shows nothing about keyword volume, backlink authority, or how competing pages are performing in search results. For on-page SEO work it is unmatched at this price point, but it needs to be paired with a metric extension for competitive research.
Completely free, no account required, and actively maintained with regular updates. Install it from the Firefox Add-ons store by searching “Detailed SEO Extension.” For bloggers, content creators, and webmasters who need fast on-page audits without a premium tool subscription, this is the first extension to install.
2. Sprout SEO
Sprout SEO is the standout newcomer in Firefox SEO extensions for 2026, and it earns its place at the top of any serious audit stack. Right-clicking on any page opens a context menu that functions like a Swiss Army knife for technical SEO — instant access to title tags, meta descriptions, canonical tags, robots directives, and heading structure. Where it genuinely separates itself from older on-page tools is its integration of Core Web Vitals data pulled directly from the Chrome User Experience Report (CrUX), meaning the LCP, INP, and CLS figures it surfaces are the same real-world performance signals Google uses for ranking — not a local Lighthouse estimate.
The SERP analysis layer is equally strong. Sprout overlays on-page metrics for every result on a search page simultaneously, which makes competitive analysis significantly faster than checking pages one at a time. For technical SEO audits, having real CrUX data and redirect chain analysis built into the same extension that handles on-page checks removes the need for multiple separate tools. It supports both Chrome and Firefox, is actively maintained, and has earned strong reviews from working SEOs who run audits daily.
Sprout SEO is free to install from the Firefox Add-ons store. For anyone building or refreshing their Firefox SEO stack in 2026, this is the extension that most deserves a place alongside Detailed SEO Extension as a core audit tool.
3. SEOquake
SEOquake by Semrush is one of the oldest and most trusted free SEO extensions for Firefox, and it remains one of the most capable tools available without spending anything. It overlays key metrics directly on Google search results — domain age, Semrush rank, number of backlinks, and indexed page count for every result on the page simultaneously. Switching from SERP analysis to page audit takes a single click, giving you keyword density, internal and external link counts, and a structured on-page report for any URL you visit.
The CSV export feature sets SEOquake apart from most free extensions. Pulling SERP data into a spreadsheet for reporting or client work is a genuine time-saver that tools charging monthly fees often reserve for paid tiers. No Semrush account is needed for the core features, though a paid Semrush subscription unlocks deeper platform integration. The practical workaround for the data-density problem is to leave the SERP overlay disabled by default and toggle it on only when actively doing competitive research. For SEO professionals and bloggers who want a free all-in-one SERP and audit tool, SEOquake remains the most capable option available.
4. Ahrefs SEO Toolbar
The Ahrefs SEO Toolbar gives instant access to Ahrefs backlink and keyword data as you browse, and the free version is more generous than most people realise. Without any paid account it shows Domain Rating, URL Rating, estimated organic traffic, and the number of referring domains and backlinks for any page you visit. The SERP overlay surfaces the same metrics for every result on a Google search page simultaneously, which makes competitive analysis significantly faster than checking pages one at a time.
The toolbar also includes a broken link checker and a redirect chain tracer as free features — both normally reserved for paid technical SEO tools. For link building prospecting, having these two capabilities built into the same extension that surfaces backlink authority removes the need for multiple separate tools. The honest limitation is that the free version becomes significantly less useful without the context of the full Ahrefs platform behind it. DR and UR numbers are meaningful when you understand how to interpret them relative to competitors — without that context they are just numbers. For existing Ahrefs subscribers, this toolbar is essential browser-level access to your data. For free users, it still provides useful at-a-glance authority checks, making it worth installing even without a paid account.
5. MozBar
MozBar is Moz’s legacy SEO toolbar and the longest-standing browser extension in the SEO industry. Its primary value is displaying Page Authority and Domain Authority — Moz’s proprietary link metrics — for any page or domain, with the SERP overlay showing these figures for every result at once. This makes it particularly useful for link building prospecting, where you need to quickly assess the authority of many potential link targets without opening each one individually.
An important caveat for Firefox users: MozBar is no longer officially supported on newer versions of Firefox as of late 2024. Chrome users may also encounter compatibility warnings. If Firefox is your primary SEO browser, the Ahrefs SEO Toolbar provides more useful free data from a larger, more frequently updated backlink index without the compatibility concerns. For Moz Pro subscribers already embedded in the Moz ecosystem, MozBar remains functional on supported setups, but it should not be the first recommendation for new Firefox SEO stacks going into 2026.
6. Keywords Everywhere
Keywords Everywhere surfaces search volume, cost-per-click, and keyword competition data directly on Google, YouTube, Amazon, Bing, and more than fifteen other sites as you browse normally. Rather than switching to a standalone keyword research tool, volume data appears inline on every search result page — which makes it significantly faster to evaluate keyword opportunities during everyday research. It also shows related keywords, trending queries, and People Also Ask data enriched with volume figures alongside the standard search results.
The tool moved from a free model to a credit-based system, where $10 purchases 100,000 credits that most users find lasts several months of regular research. Credits expire after one year. At that price point it is the most affordable paid SEO extension available — cheaper than a single month of any standalone keyword research platform. Pairing it with dedicated free keyword research tools covers both depth and browser-level convenience without significant expense. For anyone who researches keywords regularly and wants the data surfaced inline without opening a separate tool, Keywords Everywhere is worth the modest cost.
7. Mangools SEO Extension
Mangools offers a clean, beginner-friendly SEO extension that pulls data from their KWFinder, SERPChecker, and LinkMiner tools into a single browser panel. It shows domain authority, backlink counts, keyword difficulty scores, and traffic estimates for any page you visit, with a SERP overlay displaying keyword difficulty alongside each search result. The interface is noticeably cleaner and less cluttered than SEOquake, which makes it a more comfortable starting point for users who find data-heavy dashboards overwhelming.
A Mangools account is required for most of the data — a free account provides limited daily lookups, and a paid subscription unlocks the full dataset. The paid Mangools plan is more expensive than using the Ahrefs Toolbar with a basic Ahrefs account, and the backlink data depth is less comprehensive than Ahrefs. Where Mangools genuinely earns its place is for agencies and freelancers already subscribed to the Mangools platform who want browser-level access to their existing data. For new users choosing between extensions, Ahrefs Toolbar provides more data at a lower effective cost, but Mangools wins on interface quality and ease of use for beginners.
8. Link Redirect Trace
Link Redirect Trace is a specialist tool with one job — showing the complete redirect chain for any URL, including every intermediate hop, the HTTP status code at each step, and the HTTP headers being passed along the chain. For anyone who has recently migrated a site, changed URL structures, consolidated domains, or is building links and wants to verify that equity is flowing correctly through redirect chains, this extension removes the need for an external redirect checker tool.
It also detects canonical URLs, nofollow and sponsored link attributes, and provides link equity flow indicators at each step in the chain. The information it surfaces — 301 versus 302 status codes, meta refresh redirects, redirect loops — is exactly what matters when diagnosing why a page is not inheriting the authority it should from redirected URLs. It is free with no account required, but it has a genuinely narrow use case. During day-to-day content work it stays dormant — its value appears specifically during technical audits, site migrations, and link building verification. Understanding how duplicate content affects SEO becomes more actionable when you can check canonical tags and redirect chains on any page within seconds using this tool. Technical SEOs should have it installed.
9. Wappalyzer
Wappalyzer detects the technology stack of any website — CMS, ecommerce platform, hosting provider, CDN, analytics tools, A/B testing software, JavaScript frameworks, payment processors, and more. It is not an SEO tool in the traditional sense, but it is invaluable for competitive research. Understanding that a competitor runs on WordPress with LiteSpeed and Cloudflare, uses Google Analytics 4 alongside a heatmap tool, and processes payments through Stripe tells you a significant amount about their operational setup and budget.
For sales prospecting, Wappalyzer identifies potential clients running specific platforms — useful for agencies that specialise in particular CMS migrations or platform optimisations. The basic detection is free with no account required, though bulk analysis across many URLs requires a premium plan. The one meaningful limitation is that it occasionally misidentifies technologies, particularly when sites use custom configurations or obfuscate their stack deliberately. It is worth cross-referencing surprising detections with a manual check before drawing strong conclusions. For competitive intelligence work, Wappalyzer is a useful addition to any Firefox SEO toolkit.
10. SEO Minion
SEO Minion moved to a paid subscription model, which changed its value proposition significantly. It was previously the most popular free on-page SEO extension for Firefox, and its paid version continues to offer solid on-page analysis, SERP preview tools, hreflang checking, and a broken link highlighter. For users already paying for it before the model change and satisfied with the feature set, it remains functional and capable.
For anyone evaluating SEO extensions now without a prior relationship with SEO Minion, Detailed SEO Extension and Sprout SEO together cover the same on-page functionality at no cost, making it difficult to justify the subscription. The hreflang checking feature is the one area where SEO Minion meaningfully differentiates from free alternatives — for international SEO work with multiple language or region variants, that specific capability has genuine value. Everyone else should use Detailed SEO Extension instead. Building a strong SEO strategy starts with choosing tools that deliver real value for your actual workflow — not the most feature-rich paid options available.
Which Firefox SEO Plugins Should You Actually Install?
The right stack depends entirely on what you are doing. Running all ten extensions simultaneously is counterproductive — it slows Firefox, clutters the toolbar, and produces more data than any single workflow needs at once. Every extension also represents a potential security surface area, so installing from official stores and reviewing permissions before granting access is a non-negotiable baseline practice.
For bloggers and content creators, two extensions cover most needs: Detailed SEO Extension for on-page checks and Keywords Everywhere for inline keyword volume during research. Both are lightweight and the combination costs $10 per year at most. For technical SEOs, the practical stack is Sprout SEO for on-page audits combined with Core Web Vitals data, Link Redirect Trace for redirect chain verification, and Wappalyzer for competitor technology analysis. None of these three require paid accounts. For link building work, Ahrefs SEO Toolbar paired with Link Redirect Trace gives you authority metrics at the page you are prospecting and redirect chain verification on the links you are building — the two things that matter most when evaluating link targets.
For competitive research, SEOquake and Ahrefs SEO Toolbar together give you SERP overlays with both Semrush and Ahrefs metrics simultaneously, which is genuinely useful when assessing keyword difficulty from two different data sources. Beginners and freelancers who want capable tools without spending anything should start with Detailed SEO Extension and SEOquake — both completely free, covering different ground, and together handling the majority of everyday SEO browser tasks. Understanding how domain authority works adds important context when interpreting the metrics these extensions surface.
The practical rule is to install extensions one at a time, use each for a week before adding another, and disable rather than uninstall extensions you are not actively using. Keeping separate Firefox profiles for SEO research and casual browsing prevents SERP personalisation from contaminating audit data — a small habit that produces meaningfully cleaner research results over time. For a broader view of available tools beyond browser extensions, the full list of free keyword research tools covers standalone platforms that complement browser extensions rather than duplicate them.
Frequently Asked Questions
What is the best free SEO plugin for Firefox?
Detailed SEO Extension is the best free SEO plugin for Firefox. It replaced SEO Minion after that tool moved to a paid model. One click shows title tags, meta descriptions, heading structure, canonical tags, schema markup, and full link analysis — with no account required and no paid tier. Sprout SEO is a strong free complement for technical audits and Core Web Vitals data.
Is SEOquake free for Firefox?
Yes — SEOquake is completely free for Firefox and requires no Semrush account for its core features. It provides SERP overlays with domain age, backlink counts, and indexed page metrics, along with page audits, keyword density reports, and CSV export. A Semrush subscription unlocks deeper platform integration but is not required for standalone extension functionality.
Does MozBar work on Firefox in 2026?
MozBar is no longer officially supported on newer versions of Firefox as of late 2024, which limits its reliability for Firefox users. Chrome users may also see compatibility warnings. For Firefox-based link prospecting, the Ahrefs SEO Toolbar is the better choice — it provides Domain Rating and URL Rating data for free from a larger, more frequently updated backlink index without the compatibility issues.
Is SEO Minion still free?
No — SEO Minion moved to a paid subscription model and is no longer free. The best free replacement for its on-page analysis features is the Detailed SEO Extension, which covers the same functionality including title tags, headings, meta data, canonical tags, and link analysis at no cost and with no account required. Sprout SEO covers technical depth that Detailed does not.
Can I use the Ahrefs SEO Toolbar without an Ahrefs account?
Yes — the Ahrefs SEO Toolbar shows Domain Rating, URL Rating, and estimated organic traffic for free without any account. The SERP overlay and broken link checker also work without logging in. Full backlink data, keyword rankings, and detailed competitive analysis require a paid Ahrefs subscription, but the free metrics are genuinely useful for quick authority checks while browsing.
How many SEO extensions should I run in Firefox at once?
Two to three active extensions is the practical maximum before performance and toolbar clutter become noticeable problems. A well-chosen stack of Detailed SEO Extension or Sprout SEO for on-page analysis plus one metric extension like Ahrefs Toolbar or SEOquake for SERP data covers the majority of everyday SEO browser tasks without the overhead of running a larger suite simultaneously.
What is the best Firefox SEO extension for keyword research?
Keywords Everywhere is the strongest Firefox extension specifically for keyword research. It surfaces search volume, CPC, and competition data inline on Google, YouTube, Amazon, and more than fifteen other sites as you browse normally. The credit-based model costs $10 per 100,000 credits, which lasts most users several months of regular research — making it the most affordable paid SEO extension available.
What is Sprout SEO and is it better than Detailed SEO Extension?
Sprout SEO is a newer Firefox and Chrome extension that combines on-page analysis with real-world Core Web Vitals data from Google’s CrUX database. It is not strictly better than Detailed SEO Extension — it is complementary. Detailed handles meta tags, headings, and schema checks with maximum simplicity. Sprout adds technical depth including real LCP, INP, and CLS scores that Google actually uses for ranking.
Conclusion
The most capable free Firefox SEO stack right now is Detailed SEO Extension for on-page analysis, Sprout SEO for technical depth and Core Web Vitals, and SEOquake for SERP metrics — all completely free, covering different ground, and together handling the majority of everyday browser-based SEO tasks. Add the Ahrefs SEO Toolbar if backlink authority data is part of your workflow, and Keywords Everywhere if inline keyword volume during research is worth $10 a year. MozBar users on Firefox should be aware of the compatibility limitations introduced in late 2024 and should consider migrating to Ahrefs Toolbar for the same link prospecting use case.
The temptation with browser extensions is to install everything and leave it all running. That approach produces a slow browser, a cluttered toolbar, and more overlapping data than any workflow can use productively. A lean stack of two or three tools matched to actual daily tasks will deliver more value than a comprehensive but unfocused collection. Install from official stores only, review permissions before granting access, and use separate Firefox profiles for SEO research and casual browsing to keep audit data clean.
Browser extensions work best as a first layer of analysis that tells you where to look deeper, not as a replacement for dedicated SEO platforms. Use them to identify issues and opportunities quickly while browsing, then take the findings that matter into your primary SEO tool for the thorough investigation that drives actual ranking improvements.
Full-stack developer at Scylla Technologies (USA), working remotely from Bangladesh. Adobe Certified Magento Developer.
