Effective SEO means that you need to be able to crawl websites, diagnose issues, make data-driven decisions and implement changes. In other words, the quality of tools and data you use, are directly correlated with the SEO outcomes.
In this article, I’ve collected a large sample of the best free SEO tools I use in my day to day SEO workflows, covering everything you need from creating and optimizing content, to creating a search strategy and solving website performance issues.
Without further ado, these are my favorite free SEO tools in 2020:
Screaming Frog (Freemium)
Screaming Frog is a powerful SEO crawler and spider, that needs no introduction among SEOs. Moreover, it is free to use for small websites with a crawl limit of 500 URLs in the free version.
Some of the things you can do with it include scanning a website and exporting the metadata and page elements, including titles and descriptions for each page, H1 tags, alt tags for images, but also generating Sitemaps, validating AMP pages and more.
You can also integrate with APIs (such as Ahrefs’ API as an example), pull search data and directly correlate them with your crawl results. This makes screaming frog an incredibly powerful SEO tool.
What I like the most about it is that it’s very easy to use as a beginner, with a lot of advanced features for most experienced users. You can use it for small and big websites alike and extend its functionality with APIs from other tools and data providers.

MozBar (Freemium)
MozBar is a Chrome extension that brings you data insights from Moz on any page you visit. The data insights in the free version include metrics such as the Page Authority, Domain Authority, number of links to a page and Moz’s spam score.
What I like most about MozBar is that it makes important SEO metrics available at a glance in every page that you visit. It’s can also integrate in the SERPs (screenshot) and allows you to quickly view the above-mentioned metrics of top-ranking websites.

SEO Ruler (Free)
SEO Ruler is a powerful free Chrome extension made by SEO developer Pablo Rosales.
It includes over 25 SEO tools such as schema markup viewer, on-page/metadata viewer and functionality that allows you to do bulk operations in the search results, for example copying organic links and People Also Ask questions from Google Search.

Detailed SEO Extension (Free)
The Detailed SEO Extension delivers insights at the click of a button to any website you’re currently on. It’s developed by Detailed.com – an SEO research firm, and it’s an incredibly useful tool (also marketed to professional full-time SEOs).
Through its control panel, you have access to a comprehensive breakdown of all on-page SEO elements without the need to dive into the source code – it saves hours of work and makes quick on-page checks fast and easy.

Google Lighthouse
Google Lighthouse is a free and open-source, automated tool for improving the quality of web pages. You can run it from inside Chrome dev tools, but it also comes in the form of a Chrome plugin. You can use Lighthouse to audit and generate reports for a website’s performance, accessibility, Google’s best practices, and SEO.
Moreover, the audits are broken down in clear components and it provides actionable steps for improvements. If you’re interested more in open source SEO, here are a few suggestions to get you started.

Merkle’s Schema Markup Generator (Free)
Schema markup is custom code that you can add to your website to improve the way search engines read and represent your page in SERPs (it unlocks rich search results, such as in the image below).

And this Schema Markup Generator tool from Merkle, a performance marketing agency, is an easy and straightforward way to create and test schema markup for your website.
Once you’ve created and tested your schema code, you can copy and paste it into your website and you’re good to go.

Linkio’s Anchor Text Generator (Free)
This anchor text generator is created by Linkio, a tool for managing link building campaigns. What is great about it, is that it’s free, no sign-in required, and powerful.
You can add your brand name and target keywords and it will give you dozens of anchor text ideas for your links. Moreover, it can create suggestions based on the style of content you want to insert the link to (blog content, long-form content, company homepage, etc.).

Answer the Public (Freemium)
Answer the public is a consumer insights tool, that combines and visualizes the suggested searches from Bing and Google.
It’s a great way for discovering questions related to your content, expanding your topics with long-tail phrases that get search traffic, and providing answers to questions that are important to your audience.

Ubersuggest (Freemium)
Ubersuggest is a new, disruptive tool created by Neil Patel. What it offers is very close to a full SEO Suite, but without being in the ~100 USD/ month range.
It includes a keyword research tool, backlinks analyzer and more, making it one of the very few open access data-driven SEO tools in the market.

What Are Your Thoughts?
Creating a complete list of Free SEO tools is close to an impossible task. That’s why the above mentioned are not necessarily the only ones or the best ones, but rather the free tools I find myself using more often in my workflows as a full-time professional SEO.
Which ones are your favorites? I’d love to hear in the comments!
Learn more about how to leverage website-driven marketing for your online business at Studio for Digital growth. Konstantinos and his team have helped online businesses in the English-speaking and German-speaking markets grow their online reach, and make the right decisions for their websites and content.
You can also check out the episode of the podcast featuring Konstantinos talking all about SEO for Small Businesses.