The Best 5 Free Tools for Checking Domain Authority and Backlinks

One of the biggest myths about expired domain hunting is that you need a host of expensive, premium tools to get started. While the professional SEO suites offer incredible depth, there is a powerful stack of completely free tools that can provide you with all the essential data you need to find and vet your first high-quality domain. You just need to know where to look and how to use them.

This guide is for the savvy founder, the bootstrapping marketer, and the curious beginner. We'll break down the five best free tools for checking the crucial metrics: Domain Authority, backlink quality, and domain history. With this free toolkit, you can start your due diligence process today without spending a dime.

1. Unowna: For Discovery and At-a-Glance Metrics

What it is: A free, open-access dashboard for discovering expiring domains.
Why it's essential: Unowna is the ultimate starting point because it aggregates the most important top-level metrics for free. Without needing an account, you can see a live feed of dropping domains and instantly check their Domain Authority (DA), Spam Score, Backlink Count, and Referring Domain Count. Its powerful filtering system allows you to create a high-quality shortlist without ever leaving the site. It solves the biggest initial problem: sifting through thousands of domains to find the few that are worthy of your attention.
How to use it for free: The entire platform is free. Use its filters to set your baseline criteria (e.g., DA > 20, Spam Score < 15%) and use its keyword search to find relevant opportunities. This is your free mission control center. 🚀

2. Ahrefs Free Backlink Checker: For High-Level Link Analysis

What it is: A free tool from the industry-leading SEO data company, Ahrefs.
Why it's essential: Once you've found a promising domain on Unowna, you need to peek at its backlink profile. Ahrefs' free tool is perfect for this. It gives you the domain's Domain Rating (DR), the total number of backlinks and referring domains, and, most importantly, a list of the top 100 backlinks. This allows you to perform a quick but crucial quality check. You can see if the most powerful links are coming from legitimate, relevant websites or from spammy sources.
How to use it for free: Simply go to the Ahrefs Free Backlink Checker page, enter the domain, and solve the captcha. Focus on the list of top referring domains. Are they real sites? Are they in the right niche? This free glimpse is often all you need for an initial backlink quality assessment.

3. Moz Link Explorer: For DA and Top Link Insights

What it is: A powerful link analysis tool from Moz, the creators of Domain Authority.
Why it's essential: Moz offers a generous free community account that gives you a limited number of Link Explorer queries each month. This tool is the definitive source for checking a domain's Domain Authority (DA) and Spam Score. Like the Ahrefs tool, it also shows you the top links pointing to the site and the most common anchor texts. Using this in tandem with Ahrefs' checker gives you a more complete picture of a domain's authority.
How to use it for free: Sign up for a free Moz community account. You'll get around 10 free queries per month. Use them wisely on your top candidates from your Unowna shortlist. Prioritize checking the Spam Score and analyzing the top anchor texts for any spammy keywords.

4. Archive.org (The Wayback Machine): For Essential History Checks

What it is: A massive, free digital library of the internet's past.
Why it's essential: This is the most important free tool in your entire arsenal. Metrics can be manipulated, but a domain's visual history is much harder to fake. The Wayback Machine allows you to see what a domain's website looked like over the years, confirming its niche, content quality, and consistency. It's the only way to know for sure that a domain with links from pet blogs was actually a site about pets. This check is absolutely non-negotiable. 📜
How to use it for free: The tool is completely free and requires no account. Enter your target domain and spot-check several snapshots from its history to look for red flags like spam, PBN usage, or sudden topic changes.

5. Google Search: For the Ultimate Index Check

What it is: The world's largest search engine.
Why it's essential: The final and most critical test for any expired domain is to see if Google still recognizes it. The free `site:` search operator is a simple command that tells you instantly if a domain is still in Google's index or if it has been removed due to a penalty. A de-indexed domain is worthless, making this 5-second check an absolute lifesaver.
How to use it for free: Go to Google and search `site:yourdomain.com`. If you see a list of results, it's indexed (a good sign). If you see "did not match any documents," it's de-indexed (a deal-breaker).

Conclusion: A Powerful Toolkit for Zero Cost

You don't need to break the bank to get started with expired domains. By combining the discovery power of Unowna, the analytical glimpse from Ahrefs and Moz, the historical context from Archive.org, and the final verification from Google itself, you have a complete, end-to-end workflow for finding and vetting domains.

Master this free stack first. It will teach you the fundamentals of due diligence and help you find your first successful project without any financial risk on tools.