Referring Domains Checker

See which domains link to a site, built entirely on Common Crawl's free public web graph — no paid backlink API, ever. This shows referring domains (which domains link to the target at least once), not specific pages or anchor text — see the note at the bottom for exactly what that means.

100% free, forever No API key No per-lookup cost Built on open data .csv & .json export

backlinks.sqlite not found. This tool needs its data file built first.

Run build_backlink_index.py once (needs Python + pip install duckdb), then upload the resulting backlinks.sqlite file into this same folder.

How it works

Three steps, zero cost

No account, no credit card, no monthly plan — the data was already gathered for free by Common Crawl; this tool just makes it searchable.

Enter a domain

Type in any domain or URL — yours, a client's, or a competitor's.

We check the index

A pre-built index from Common Crawl's open web graph is searched instantly — nothing is fetched live per lookup.

See who links to you

Get referring domains sorted by size, with full CSV/JSON export of everything found.

Who it's for

Built for people priced out of the big tools

🏢 Small business owners

See who's already linking to your site without paying for an Ahrefs or Semrush subscription you'd barely use.

💼 SEO consultants & freelancers

Run a quick client audit without burning your own paid tool credits on a one-off check.

📍 Local marketers

Spot which local directories and community sites you're missing from compared to competitors.

📰 Content & PR teams

Track which sites picked up a press mention or guest post, without a monitoring subscription.

FAQ

Common questions

Is this really free, with no catch?

Yes. It's built on Common Crawl, a nonprofit's free public web crawl data — there's no API key, no account, no per-lookup fee, and no plan to add one.

How is this different from Ahrefs or Semrush?

Those tools crawl the web continuously themselves and sell access to that index. This tool uses the same kind of underlying data, but from Common Crawl's free public dataset, updated every 1–3 months rather than continuously — the trade-off for zero cost.

Why wasn't my domain found?

Either it's too new or small to appear in Common Crawl's crawl yet, or it genuinely has no known referring domains in this dataset yet.

How fresh is this data?

As fresh as the last time this tool's index was rebuilt from a Common Crawl release, which happens every 1–3 months. A link from last week may not show up immediately.

What's a "referring domain" vs. a full backlink list?

A referring domain means "this domain links to you somewhere." It doesn't show the exact page or anchor text — that level of detail needs infrastructure this free tool doesn't use.

Can I export the results?

Yes — Download .csv or .json gets you the complete list of referring domains found, not just the top rows shown on screen.

This tool is built entirely on Common Crawl's free, public domain-level web graph (no paid backlink API, no per-lookup cost, no account required). It shows referring domains — which domains link to the target at least once — not specific pages, URLs, or anchor text; that level of detail lives in a vastly larger Common Crawl dataset this tool doesn't query, since doing so live would need paid cloud query infrastructure, the exact cost this tool exists to avoid. Data refreshes only when the index is rebuilt from a newer Common Crawl release (every 1–3 months), so very recent links won't show up immediately, and very small or brand-new domains may not appear in Common Crawl's crawl at all. Domain parsing uses a common-case public suffix list; unusual multi-part country-code domains may not resolve correctly.