Find similar websites and check why they match

To find similar websites, define what you want the sites to have in common, choose a signal that measures it, then check the candidates against current pages. A shared link neighborhood can suggest related publications; shared search queries can suggest search competitors. Neither establishes that two companies sell interchangeable products.

This guide gives you a repeatable way to turn a domain into a useful shortlist. You need one starting website, a clear research purpose and somewhere to record your evidence. The worksheet below is an editorial research framework, not a tested scoring model or a ranking guarantee.

1. Write the decision the shortlist must support.
2. Choose a similarity signal that fits that decision.
3. Generate candidates and record the source date.
4. Inspect the evidence behind each candidate.
5. Validate current relevance and choose a next action.

1. Define what similar websites should share

Start with a sentence such as: “Find publications that cover trail running for recreational runners in the UK.” That sentence makes topic, audience and geography explicit. It also gives you a reason to reject a running-shoe shop even if the shop appears close to the publication in a link graph.

A useful shortlist has a job. You might be looking for alternative suppliers, competing editorial coverage, potential sources for an article or websites serving the same buyers. Those tasks need different evidence. A site can belong on one list and be unsuitable for another.

Done means another researcher could read your purpose sentence and make a defensible inclusion decision. “Interesting websites” is too loose. “English-language resources explaining mountain race preparation” provides a workable boundary.

2. Choose a signal for finding similar websites

Tools use different definitions of similarity. Semrush describes its Competitor Finder in terms of shared organic keywords. Similarweb documents category and affinity within its Similar Sites feature. These are vendor descriptions of their own tools, reviewed on 26 September 2026, rather than an independent performance comparison.

LinkCensus starts from dated Common Crawl link patterns. Its ranking and retained shared-linker explanations help you examine a website’s graph neighborhood. That is useful when you want related sites beyond an obvious product-category list. It does not measure competitor traffic, shared customers or business ownership.

Use keyword overlap for a search-content question, product inspection for a purchasing question and link context for a discovery question. You can combine them, but keep each observation in its own column. A single “similarity” label hides which question the evidence actually answers.

Read the LinkCensus method and coverage limits before interpreting a result. In particular, an embedding score is not a count of shared websites. The accompanying shared-linker evidence has its own retention limit and should be read separately.

3. Generate candidates and preserve the date

Use the domain that represents the entity you mean to research. Check that it opens the intended website and is not an old brand domain, a redirect to a parent company or a hosting platform shared by unrelated organizations. Record the input exactly so the search can be repeated.

For link-based discovery, start a related-domain lookup in LinkCensus. Save the edition shown alongside the result, the day you ran the lookup and the reason each candidate caught your attention. The edition identifies the dated artifact behind the result; today’s lookup date does not make that artifact a live crawl.

Keep the initial list small enough to inspect. There is no universal correct number of candidates. If you have time to open only ten sites, collecting a thousand rows merely moves the selection problem into a spreadsheet. Start with a manageable batch and expand only when the inspected candidates fail to cover the decision.

Done means each candidate has a traceable origin. “Found in LinkCensus, edition shown in result, inspected on this date” is more useful than a bare domain pasted into a document.

4. Inspect why the candidate appeared

A shared linker is a source domain that links to both targets in the evidence being compared. The links may occur on different pages of that source domain. They do not establish that the two targets were mentioned together in one paragraph or endorsed for the same reason.

LinkCensus labels this evidence shared linkers (among top 200 retained). The retained overlap can explain part of a relationship without showing every observed linker. See the worked co-citation example for the difference between an overlap count and a normalized score.

Inspect the character of the sources. A specialist association, a general directory and a technical resource host carry different kinds of context. Common Crawl’s web-graph documentation says its graphs include resource links such as images, scripts and fonts. A graph edge therefore needs interpretation before you call it an editorial recommendation.

When the product supplies domain-level evidence, open the current source site only if that helps the decision. You may need a separate page-level search to locate the relevant link. If you cannot find it, record “historical graph evidence, current page not located.” Do not silently upgrade that into a current link verification.

5. Check current relevance before keeping a site

Open the candidate’s current homepage and one or two pages relevant to your purpose. For a supplier, those might be product and service-area pages. For a publication, inspect its recent articles and editorial description. Record a specific URL that supports your classification.

Classify the candidate as a competitor, publication, supplier, source or unrelated result. Allow more than one label when the evidence supports it. A magazine with a shop may be both a publication and a commercial competitor for one narrow product line.

For business-competitor decisions, use the separate checks in the website competitor research worksheet. Sharing a link neighborhood is a starting observation. Claims about ownership or partnerships require direct evidence from the organizations or appropriate corporate records. The website ownership evidence guide separates the registrant, site operator and brand relationship when those names matter to your shortlist.

Try the worksheet with Stripe

Start with stripe.com and a purpose: find sites worth comparing for payment processing. Stripe’s Payments page, checked on 11 October 2026, describes a unified payments solution, which fits that purpose. On the same day the LinkCensus public Stripe sample showed results for stripe.com in edition 2026-01, whose host graph covers November 2025 to January 2026. The sample report preview (new tab) listed five rows: termly.io, mailchimp.com, wistia.com, ghostery.com and adyen.com. The lookup date describes this editorial check. The evidence still comes from that dated edition, not from a fresh crawl.

Two of those rows show why the worksheet asks for the retained evidence and the current page separately.

Adyen is worth comparing with Stripe because the Adyen homepage describes a payments product. Adyen’s 50 shared linkers with stripe.com (among top 200 retained) cannot establish that category on their own. Ghostery has 40 shared linkers with stripe.com (among top 200 retained), including google.com and wordpress.org, and still does not fit a payment-processing comparison, because the Ghostery homepage describes ad and tracker blocking. Keeping Adyen means only that Adyen is worth comparing with Stripe on capabilities, buyer segment and service region. The Stripe sample is not evidence of a partnership, an endorsement or shared customers between Stripe and Adyen.

Read google.com and wordpress.org as historical retained host names from edition 2026-01. The Stripe sample names linker domains, not the pages that carried the links, so no current link from either host to Stripe, Adyen or Ghostery was verified for this example. That status is unknown. The counts are overlaps among the top 200 retained, not backlink totals. Record the edition, the lookup date, the named linkers and the pages you checked, and leave current link status as unknown until you have inspected an exact source page. To repeat the check, open the free Stripe lookup; the preview follows the public sample, so later rows may differ.

Keep a decision log and handle missing results

Copy these fields into a sheet: candidate domain; research purpose; discovery source; source edition or capture date; current page checked; date checked; classification; supporting observation; uncertainty; next action. Keep observations separate from conclusions so a colleague can revisit a decision without rerunning the whole search.

If a site is missing, first check the spelling and domain scope. Then consider whether the site is new, small or outside the retained edition’s coverage. Missing results do not prove that a site has no links or no related organizations. Try a different starting domain or use a different signal that matches the research purpose.

A finished shortlist should tell you what to do next: inspect a publication’s relevant archive, compare a supplier’s stated capabilities or exclude a candidate that serves a different market. Save the evidence with that action. The value comes from the decisions the list supports.