Written by Crystal Ortiz. Updated on 21, February 2024
We've tested some of the most recommended SEO extensions and put together this list with the best free ones.
You're about to learn how to use this elite selection of tools to elevate your SEO without breaking the bank.
The extension's top features include:
This gives you access to Google Search Console data while browsing and removes the need to open the SEOTesting dashboard every time you want to check a page - that's a big time saver if you ask me.
Regardless of whether you have a SEOTesting account, the extension offers valuable features, such as:
I use the document structure all the time to confirm the content and headings are correct.
Note: Clicking on a heading will scroll down to that page element, and hovering your mouse will highlight it.
Grammarly has a free browser extension offering grammar, spelling, and tone suggestions to keep your writing sharp virtually everywhere, whether you're writing emails or articles.
This extension will be your best companion to avoid awkward mistakes.
Grammarly's free plan is generous. I started using the free plan in 2017 and changed to the paid subscription in 2021.
I use it all the time to check my articles (like this one you're reading) to ensure it is easy to read.
You can set a preferred tone, which will help you write consistently. My default is informal writing with an informational goal.
These tailored suggestions are one of the things that makes Grammarly a breeze to use.
Keyword Surfer extension lets you see search volume and CPC for the keywords in the SERP.
They have search volume data for more than 70 countries, including the USA, United Kingdom, Australia, France, and Germany.
Within the SERP, Keyword Surfer will show an info box with the website's estimated traffic, words on the page, and the number of exact matches for the query.
It will even let you know when Google rewrites a page title. Following Google’s renewed interest in changing title tags, this feature from Keyword Surfer is a complete game changer.
You'll see a useful Keyword Surfer widget on the right side of the SERP.
It has keyword ideas, their similarity to the current query, and the respective search volume.
You can quickly press the star to save these keyword ideas to the clipboard.
This extension adds the following widgets to SERP's right-hand side:
Furthermore, Keywords Everywhere also shows traffic estimations and the keywords each page ranks for.
This extension works with most platforms, including:
Keywords Everywhere premium plan involves a credit system that starts at $10. I find that $10 worth of credits per year is more than enough to research keywords for one website.
These credits are necessary to show keyword search volume, CPC, and competition.
Keywords Everywhere get their keyword data from Google Ads Keyword Planner (GKP) and Clickstream.
Glimpse is an extension that enriches your Google Trends experience.
Some of Glimpse's features include:
Data shown by Glimpse is valuable for spotting new trends before they go mainstream. This can help establish yourself as an authority for up-and-coming topics while SEO competition is still low.
Furthermore, by subscribing to their newsletter, you'll get 2 exponential trends per month delivered to your inbox.
Glimpse's free plan allows 10 searches per month, and all you need is to create an account to start using it.
SimilarWeb extension shows key website metrics, like:
The extension is 100% free; the only requirement is joining their contributor network. This means you'll share information with SimilarWeb about the sites you visit.
This is a valuable extension for competitor research that you can pair with SimilarSites for more profound knowledge.
SimilarSites can show related websites to the one you're currently looking at.
The primary use case for SimilarSites is finding who are main competitors. This is helpful when you don't know much about a niche and don't want to rely on intuition. Meaning, in a lot of cases, this extension is going to be extremely helpful if you work at an SEO agency and need to research competitor sites for a client you do not know much about.
You only need to click the extension icon when visiting a site, and it will show the panel with data.
Inside the panel, you can also see the estimated monthly visitors for the competition and their ranking in the category.
Since this is an extension from SimilarWeb company, you'll need to sign up for the contributor program.
Schema.dev created this extension to help you see a page's markup.
This extension not only can help you write Schema, but it can also help you validate the Schema that's already on the page, so you can correct any errors with little effort.
It also makes it easy to use and test markup with the click of a button.
Schema Builder is handy when you need to add structured data to an e-commerce store.
Markup requirements and recommendations will also be shown when you test and deploy using the extension.
View Rendered Source is an extension to show how the browser rendered a page versus its original source code.
SEOs can use this to know what the DOM looks like and what search engines see.
This makes it possible to catch errors before Google. Otherwise, Google can index the version that's not properly rendered.
View Rendered Source divides the code into 3 sections:
Link Redirect Trace (LRT) can help you diagnose and analyze redirect errors.
What's different about this SEO extension versus its alternatives is that it shows you errors, how to fix them, and what impact the errors might be having on your site.
LRT can detect how many redirect loops there were for the current page you're visiting and the HTTP code used for each redirect.
All this is entirely free and without creating an account!
SEO Search Simulator by NightWatch simulates Google searches from different locations in real time.
This way, you don't need to use a VPN to see how a page ranks in a different country or to remove personalized Google results.
This extension is an excellent alternative to logging into SEMrush or another rank tracker tool to quickly check rankings.
It's also helpful to check how competitors rank for certain queries.
The search simulator allows saving searches, which is handy when you use the same query repeatedly.
The Detailed SEO Extension helps with on-page SEO checks.
The default section is the overview and shows elements like:
Detailed has a shortcut for each site robots.txt and XML sitemap. However, they attempt to guess where these files are located. But if these files don't exist, the shortcut will still be there and direct you to a broken link (i.e., a 404 page).
A funny example is that clicking on the sitemap shortcut for the extension's creators returns a 404 page.
The other Detailed SEO Extension features include:
This can help prevent you from following an SEO tool's character recommendations that actually cut off your titles and meta descriptions.
SEO Minion is useful for everyday tasks like finding broken links, the page HTTP status code, internal links, and if the page is indexable.
It can also help you find the following on-page elements:
The SEO Minion extension also includes a widget for the SERP.
This widget will show how many results are on the page, including Ads and organic results, but also rich results like product listings or FAQ data.
One last cool thing about SEO Minion is the possibility to download People Also Ask (PAA) questions and answers for research into a CSV file.
MozBar is a popular tool for Chrome with many capabilities for free that can analyze a page's load time, canonicals, status code, and markup.
When you're on the SERP, this extension shows Moz's most popular metrics: Domain Authority (DA) and Page Authority (PA).
MozBar free plan also includes access to link metrics from 3 places:
A common use case for MozBar is when you're working on a link-building campaign and want to see which top results in the SERP have the highest authority.
Buzzmarker from BuzzStream is an extension to help with prospecting and outreach campaigns.
This extension has a lot of advanced features that you can use while browsing, including:
When you're on the SERP, Buzzmarker can quickly analyze the results and show a prospect list that you can add to the project or review individually.
Although not completely free, it offers a 14-day free trial, so you can figure out if this is the tool for you.
Link Grabber is a free SEO extension that collects all the links from an HTML page with a click of a button and displays them in a list.
This is a great tool if you don't have Screaming Frog available or just want to do a quick check. Then you can copy these links into a spreadsheet to proceed with the analysis.
You can also group links by domain, hide duplicates, or block domains to remove them from the list.
Hunter's browser extension makes it easy to find email addresses on the web.
Their free plan includes 25 searches per month which are enough for occasional use. It is worth noting that if you are researching lots of emails for ongoing link-building work, you will need to upgrade to one of their paid plans.
When Hunter finds an email address from the site you're visiting, it will light up (turn orange) or stay gray when it doesn't. This means the extension works in the background and gives you cues while you perform other tasks.
Clicking on the extension icon shows a pop-up window with the known email addresses and URL sources where they were found.
Alternatively, Findymail can also enrich a list of websites directly if you don't want to visit each website individually.
Turn into the Siteimprove Accessibility Checker extension to find useful insights into your website's accessibility.
This tool lists all the accessibility issues and how often they happen on the page. Heck, it will even point to the element responsible for the warning!
This accessibility checker comes in handy when advising a potential client on the necessity of accessibility compliance, and you want to show examples as to how they can improve.
Overall, it's a straightforward extension to improve the web experience for users with disabilities.
SEOQuake is a popular SEO extension capable of a wide range of tasks that you can use for free or with a paid Semrush account.
The latter option provides advanced backlink reports and traffic data, using the extension's full potential.
You can use SEOQuake analytics to quickly make a page diagnosis. Here's a summary of what you can find:
On Google, SEOQuake shows an info box below each result containing the number of pages indexed for the domain and the number of backlinks. There's also an export button on the left side of the SERP.
They also have an 'SEO bar' for when you're using the browser with domain metrics (similar to the one on Google SERP).
Lighthouse is a Google tool to measure performance, accessibility, best practices, SEO, and correctness of progressive web apps (PWA).
Visit a page you're interested in analyzing and press the extension icon to get a report.
They'll rate each category from 0 to 100, alongside the passed audits and opportunities for improvement.
Performance is a popular section amongst SEOs since this focuses on Core Web Vitals (CWV) metrics. The “SEO” score is also another popular metric that SEO professionals will use as it will help them catch errors on their site.
Web Vitals is an open-source extension created by the Google Chrome team to measure a site's performance on the current browser.
This tool looks at the following metrics that are part of the Web Vitals:
The Web Vitals extension gives instant feedback about the site's health, and this data tends to be in line with other Google reports about Core Web Vitals like Google Search Console or Page Speed Insights.