# Similar sites by co-citation vs keyword overlap: a head-to-head

> One method counts shared Google rankings, the other reads shared mentions. Run them in the right order and keep the roundups in view.

URL: https://claudegpt.si/news/similar-sites-by-co-citation-vs-keyword-overlap  
Published: 2026-10-26T05:07:44.790Z  
Author: ClaudeGPT Si Newsroom  
Section: Reviews  
Topics: Similar sites, Co-citation, Competitor research  
Publisher: ClaudeGPT Si

## Key takeaways

- Keyword overlap groups domains that rank for the same Google searches; co-citation groups sites that the same pages mention.
- seogeoaeo.ai's Competitor Finder returns up to 30 overlap matches in a minute for 38 credits; co-citation is free but manual.
- Co-citation catches offline and ad-only rivals and yields the roundup pages worth checking for changes.

Finding similar sites by co-citation and finding them by keyword overlap sound like two routes to the same list. They are not. Co-citation groups sites that writers mention together. Keyword overlap groups sites that rank for the same Google searches. Start from one competitor with each method and you will get two lists that share some names and disagree on many. This head-to-head shows where each method is strong, where it breaks, and the order to run them in.

## The two methods in brief

**Co-citation.** Two sites are co-cited when one page mentions both. Pick two brands you already know are peers, put each name in quotes, and search for pages containing both. List every other brand those pages name. Names that recur across many pages form the cluster.

**Keyword overlap.** Take every keyword a domain ranks for in Google, compare that set with other domains, and rank the domains that share the most. This needs a keyword index, which is what [seogeoaeo.ai's Competitor Finder](https://seogeoaeo.ai/tools/competitor-finder) provides. Enter a domain and a Google country and it returns up to 30 domains with shared keywords, total keywords, estimated monthly visits and average rank.

## Head-to-head

| | Keyword overlap (Competitor Finder) | Co-citation (manual search) |
| --- | --- | --- |
| Signal | Shared Google rankings | Shared mentions in articles |
| Output | Up to 30 domains with numbers | Names you collect by reading |
| Time | A minute | An hour or more |
| Cost | 38 credits a run | Free |
| Handles giant sites | Sets them apart; 5%+ overlap marks a close competitor | You judge each page yourself |
| Finds media and blogs | Yes, if they rank for the same terms | Rarely; they are the pages, not the names |
| Finds offline or ad-only rivals | No | Yes, if writers mention them |
| Repeatable | Same input, same data | Depends on your search and patience |

## Where keyword overlap wins

It is fast, it gives you numbers, and it is honest about scale. The overlap share is the key figure: a niche site where a tenth of its keywords match the competitor's is a far closer twin than an encyclopedia that matches a few hundred out of millions. Competitor Finder sets that second kind apart so the top of the list is usable.

It also surfaces sites you would never think to search for, like the blog or forum quietly taking the clicks you want. Those rarely appear in a buyer's roundup but they matter for content planning.

## Where co-citation wins

It sees what keyword data cannot. A rival that sells through a field team, a brand that only buys ads, or a new product with almost no rankings can still be written about. Co-citation catches them.

It also hands you a second list for free: the pages themselves. Every roundup that names two of your peers and not you is a page where you want to be mentioned. Those same comparison pages are the material AI assistants learn from and cite, so they shape which brands an AI answer puts side by side.

## Which wins overall

For a first pass, keyword overlap. It turns one domain into a ranked list in a minute, with the noise filtered, and the list is the same tomorrow. Then run co-citation on the two or three closest matches to fill the gaps. Starting with co-citation means spending an hour reading before you know which brands are worth the search.

## Keep the roundups in view

The co-citation pages are not static. Roundups get updated, new comparison posts appear, and a page that left you out last month may add a rival this month. Once you have the list of pages that matter, save them and check them on a schedule, or put them under a page monitor, so you see the change when it happens rather than at your next quarterly review.

## Limits worth knowing

Competitor Finder covers whole domains and one country per run, and its visit and keyword figures are estimates. It does not track rankings over time; if you need daily positions, a suite with a rank tracker is the better fit. Co-citation has no numbers at all, and it is only as complete as your searches.

## Cost

Competitor Finder is 38 credits per run. seogeoaeo.ai plans start at $29 a month for 2,000 credits, prices show before each run, and runs that fail before producing a result are refunded. To see which domains link to a cluster rather than only mention it, Backlink Finder lists the 100 strongest linking sites for 70 credits.

Start with [one overlap lookup on the competitor's domain](https://seogeoaeo.ai), then search its closest matches in pairs.

## Frequently asked questions

### What is co-citation?

Two sites are co-cited when one page mentions both. Searching for pages that name two known peers reveals the rest of their group.

### Which method should I run first?

Keyword overlap, because it turns one domain into a ranked list quickly. Then run co-citation searches on the closest matches.

## Sources

- [Competitor Finder](https://seogeoaeo.ai/tools/competitor-finder), seogeoaeo.ai
- [Backlink Finder](https://seogeoaeo.ai/tools/backlink-finder), seogeoaeo.ai
- [seogeoaeo.ai pricing](https://seogeoaeo.ai/pricing), seogeoaeo.ai
- [Similar sites: how to find websites like a competitor](https://seogeoaeo.ai/blog/similar-sites), seogeoaeo.ai