How is this different from SimilarWeb?

SimilarWeb infers similarity from clickstream/audience data they buy from ISPs and panels. We infer it from the public link graph. Both signals are useful: link-based similarity is stronger for SEO use cases (competitor research, link prospecting); audience similarity is stronger for paid-marketing use cases.

Why are some big sites missing?

We need the input domain to have at least a handful of referring domains in the latest crawl. Sites blocked by robots.txt, behind login walls, or very new may have sparse data and return fewer (or no) similar sites.

How fresh is the data?

The current dataset is built from our Q1 2026 dataset. New crawls ship every quarter.

Can I get more than 25 results?

The free tool caps at 25 to keep it readable. The /v1/similar-domains API endpoint supports up to 100 results per request. Sign up for an API key (first 100 credits free).

Free tool

Find websites similar to any domain.

Enter a domain and we'll surface sites with overlapping referring-domain footprints, useful for competitor research, link prospecting, and partnership scouting.

About

About this tool

Background

Two websites are "similar" in SEO terms when they share a meaningful slice of the same backlink sources. If 200 different domains link to both Stripe and Square, that overlap tells you they operate in the same competitive space, far more reliably than tag-based or category-based heuristics.

RankParse builds this graph from our 3 billion-page web index. We pull the top referring domains for the input site, then count how often those same sources also link out to other sites. The result is a ranked list of competitors weighted by shared link sources, not by editorial guesswork.

How it works

Submit a domain and we sample its top 50 referring domains, then walk their outbound links to find the most common co-cited targets. The output is a ranked list of up to 25 similar sites with an "overlap" score: the number of referring domains that link to both.

Anonymous users get 5 free checks per day. Sign up free for 25/day. Need bulk? The same data is on the REST API as /v1/similar-domains, with the first 100 credits free on signup.

API

Need this for 1,000 domains?

The same data is available via the REST API. Pay only for what you use; credits never expire.

Get an API key

# Same data, programmatically. First 100 credits free on signup
curl "https://api.rankparse.com/v1/similar-domains?domain=example.com" \
  -H "X-API-Key: rp_your_key"

FAQ

Frequently asked questions

More checks on the free tools page.

Beyond the free tools

Want your agent to run these for you?

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