Backlink Guide: What are Backlinks & How to Check Them for Free

Table of Contents

What are Backlinks?
Types of Backlinks
Key Backlink Metrics Explained
How to Check Your Backlinks for Free
How to Build Quality Backlinks

What are Backlinks?

A backlink (also called an inbound link or external link) is a hyperlink on one website that points to a page on a different website. When Site A links to Site B, Site B receives a backlink from Site A.

Google's original PageRank algorithm treated backlinks as votes of confidence — the more trusted sites that link to a page, the more authoritative that page must be. While Google's algorithm has evolved enormously, links from authoritative and relevant sources remain one of its strongest ranking signals.

💡 Simple analogy

Think of backlinks as citations in academic research. A paper cited by 50 other respected papers is more credible than one cited by 2. Websites work the same way.

Types of Backlinks

Not all backlinks are equal. Understanding the difference helps you focus link-building efforts effectively:

DoFollow links — the default link type. Passes "link equity" (also called PageRank or "link juice") from the linking site to yours. These are the most valuable for SEO.
NoFollow links — contain a rel="nofollow" attribute that tells Google not to pass link equity. Common on forums, blog comments, and sponsored content. Less direct SEO value but can still drive traffic.
Sponsored links — marked with rel="sponsored". Used for paid placements. Google expects advertisers to use this attribute.
UGC links — rel="ugc" marks user-generated content like forum posts and comments. Treated similarly to nofollow.

Source type	Value	Difficulty
Editorial mention in news/blog	Very high	Hard
Guest post on relevant site	High	Medium
Resource page listing	Medium	Medium
Forum / community mention	Low	Easy
Directory listing	Low	Easy

Key Backlink Metrics Explained

SEO tools measure backlink quality using several proprietary metrics:

Domain Authority (DA) — Moz's 1–100 score predicting how likely a domain is to rank in search results. Higher = more valuable.
Domain Rating (DR) — Ahrefs' equivalent of Domain Authority, based on the quality and quantity of backlinks to the root domain.
Trust Flow — Majestic's measure of how many clicks from trusted seed sites would reach a page through its backlinks. Correlates with trustworthiness.
Referring Domains — the number of unique root domains linking to a page. More important than total backlink count — 100 links from 100 different sites is better than 100 links from 1 site.

How to Check Your Backlinks for Free

Multiple platforms offer free backlink data. Our Backlink Checker generates direct links to each platform for your domain:

Open the Backlink Checker tool.
Enter your domain — e.g. yoursite.com (no need for https:// or www).
Click Check Backlinks — direct links to Ahrefs, Moz, SEMrush, Majestic, Open Link Profiler, and Ubersuggest appear.
Click any platform to open your domain's backlink report.

Check backlinks for any domain across 6 major SEO platforms — Ahrefs, Moz, SEMrush, Majestic and more.

Open Backlink Checker →

How to Build Quality Backlinks

Link building is the practice of acquiring new backlinks to improve your site's authority. The most sustainable strategies:

Create linkable assets — comprehensive guides, original research, free tools, and data-rich resources attract natural backlinks.
Guest posting — write valuable articles for relevant blogs in your industry. Most allow a link back to your site in the author bio or body.
Broken link building — find broken links on relevant sites and offer your content as a replacement.
HARO (Help a Reporter Out) — respond to journalist queries to earn mentions and links in news articles.
Resource page outreach — identify pages that list resources in your niche and suggest your content as an addition.
Digital PR — create newsworthy content (surveys, studies, interactive tools) that journalists naturally want to link to.

⚠️ Avoid these

Buying links, participating in link schemes, and using private blog networks (PBNs) violate Google's guidelines and can result in manual penalties that dramatically tank rankings.

Frequently Asked Questions

There is no fixed number — it depends entirely on how many quality backlinks your competitors have for the same keyword. Use a backlink checker to analyse the top-ranking pages for your target keyword and aim to match or exceed their link profile quality. For low-competition keywords, you may rank with very few backlinks.

Not entirely. While nofollow links do not pass direct link equity, they can still drive significant referral traffic. They also contribute to a natural, diverse link profile — a site with 100% dofollow links can look suspicious to Google. Links from high-traffic sites like Wikipedia, Reddit, or major news outlets are valuable even if nofollowed.

Google typically discovers and indexes new backlinks within a few days to a few weeks. The effect on rankings may take weeks to months, depending on how frequently Google crawls both sites, the authority of the linking domain, and the competitiveness of the keyword.

A toxic backlink comes from a spammy, low-quality, or irrelevant site and can negatively affect your rankings. You can request removal from the linking site or use Google Search Console's Disavow Tool to tell Google to ignore specific links. The Disavow Tool should be used carefully — disavowing good links by mistake can harm rankings.

Try our free Backlink Checker — instant results, no sign-up required.