We sell link data by the call, from our own crawler and our own index, to people who wire things into publishing flows.
Contentin research team ·
What Contentin is
A developer REST API and a free online explorer. They return backlinks, referring domains, anchor text, top pages and a 0 to 100 Domain Rating for any domain, as JSON.
The index covers 181,132,097 domains, 2,774,625,913 domain-to-domain links and about 798.5 billion backlinks. It refreshes roughly once a month, so a link from last week may not be there yet.
We write for teams on a CMS or headless stack. Think webhooks, publishing hooks, field mapping and a back link checker step in a release flow. Dashboards are not our centre, and that is deliberate. Simple as that.
Who we write for
Our reader runs a content model, not a spreadsheet of keywords. They have an editor who presses publish, a webhook that fires, and a function that decides what happens next. We want link data to fit inside that function. That is the whole idea.
That reader asks different questions from a classic SEO. Where does the call go? What does a 402 do to a release? Which field holds the score? Those are the pages on this site, and you can find them in the cost table and the field guide.
Small teams gain most. A six-person product group on a static site has no analyst to open a suite each time. A hook that tags risky entries is a better fit. It runs at 3 am and nobody notices.
Agencies that look after several headless sites can use the same pattern per client key. Keep one key per site so spend stays readable.
The service in four numbers
domains in our index
181,132,097
one credit
$0.0001
free credit on sign-up, no card
$100
free actions: domain, overview, stats, suggest
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How we describe the data
Every number on this site comes from one source. Just one. Our crawler visits the public web, and our index turns that into domains, links and a Domain Rating. We do not name outside data providers because there are none to name.
The Domain Rating formula is public: round(100 · log(ref_domains+1) / log(2·10^7)). It is a log scale, so early gains are quick and later ones are slow. It is comparable in spirit to Ahrefs DR or Moz DA, never identical to them. Keep that in mind.
We try to say what a number cannot do. A score is not a ranking. A refresh in October 2026 will not show a link built in November, so plan your checks with that lag in mind.
Questions we hear most are practical. Can I test without a card? Yes, the free actions need no key. Can I run it from a browser? CORS is open, so yes. Can I pull 2,000 domains at once? bulk_dr takes that many for one credit, and the runbook shows where it fits.
What we leave to others
We are not a keyword tool. We do not track rankings or run a daily-fresh crawl. For those jobs Ahrefs and Semrush are the fuller products, and we say so.
Payment is prepaid credit. Sign in is by Google account only, and top-ups are in USDT (TRC-20) from the account page. There is no subscription and no monthly minimum.
Questions about your account, a top-up or your data go through the account page once you are signed in. We do not publish a mailbox on this site.