Backlink checker
Enter a domain or the URL of a page. You get how many links point at it, from how many different sites, a 0 to 100 rank for its link profile, and the 10 strongest sites linking to it with the page and anchor text of each link.
No account. No credits.
Beyond the top 10
See every link, not just the strongest
Backlink research in IndexZero lists every backlink, referring domain and most-linked page, can hide spammy links, and keeps snapshots of your own site's profile so you can see it change. The free plan includes 2,000 credits a month. No card needed.
The strongest links are a spot check
Take the link research further with your agent
IndexZero's MCP server has the same backlink data without the free tool's limits. get_backlinks_overview returns a domain's totals, and get_backlinks_profile lists up to 1,000 of its links, referring domains or most-linked pages, for your site or a competitor's. The free plan includes MCP access and 2,000 credits a month, and each run spends credits.
Pull the backlinks overview for my site and for [competitor.com], then list the referring domains of both and show me the sites that link to the competitor but not to me, strongest first.
Where the links come from
Each check reads DataForSEO's backlink index, built by its own crawler, which follows links across the web much as Google's does. The counts are links it has found and seen live on its latest visit. Links it once found and can no longer see are left out.
A domain counts links to every page on the site and its subdomains, and leaves out links from the site to itself. A page URL counts links to that one address. Either way, links to a URL that redirects to the target, or that names it as the canonical version, count too, since search engines pass their value along.
How to read the numbers
Backlinks
Every link found, including many from the same site. A sitewide footer link can add thousands on its own, so this number swings more than it matters.
Referring domains
How many different sites link at least once. This is usually the better measure of a link profile: ten links from ten sites say more than a hundred from one. Subdomains of the same site count separately.
Rank
DataForSEO's score from 0 to 100 for how strong the target's link profile is, calculated from the links pointing at it and the strength of the pages they come from, in the spirit of the original PageRank. It is not a Google metric. Use it to compare sites with each other.
Broken backlinks
Links pointing at pages on the target that answer with an error. Each one is a link whose value is lost. Redirecting the broken address to the closest live page usually recovers it.
Strongest linking sites
The 10 linking sites with the highest rank, showing one link from each: the page it is on, where it points, its anchor text, and whether it is a followed link or marked nofollow.
Why backlink tools disagree
Every backlink tool runs its own crawler, and none sees the whole web. Counts from Ahrefs, Semrush, Moz and this checker differ, sometimes by a lot, and Google Search Console shows yet another sample. None of them is wrong; they found different links.
Compare numbers from the same tool. The trend over time and the gap to a competitor measured the same way say more than any single count.
Why there is a daily limit
Every check buys data from DataForSEO, which IndexZero pays for. To keep the tool free and without an account, each visitor gets a limited number of lookups a day, the tool has a daily limit overall, and a quick browser check runs before each one. A target checked in the last day is served from a cache and does not count again.
The limits reset at midnight UTC. The tool only answers its own page: scripts and agents get the same data from IndexZero's MCP server, where research is paid for from a workspace's credits.
Frequently asked questions
- Is this backlink checker free?
- Yes. There is no account and nothing to pay. Each check buys backlink data that IndexZero pays for, so there is a daily limit per visitor and a short browser check before each lookup.
- Where does the backlink data come from?
- From DataForSEO's backlink index, built by its own web crawler. The counts cover live links only, and leave out links from a site to itself.
- Why does it show different numbers from Ahrefs, Semrush or Search Console?
- Each of them crawls the web separately and finds a different sample of links. Compare numbers from the same tool, and look at referring domains more than raw backlink counts.
- Can I check the backlinks of a single page?
- Yes. Enter the full URL of the page and the check counts links to that address, plus links to URLs that redirect to it or name it as canonical. Enter just the domain to count links to the whole site.
- Why do I only see 10 links?
- The free check lists the 10 strongest linking sites, one link each, beside the totals. Backlink research in IndexZero lists every link, every referring domain and your most-linked pages, and keeps a history for your own site.
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