# Signatures

Give PublicWWW a set of websites, and it finds code that lets you find more websites like them: the platform they are built on, a theme or plugin, a tracker, the network or company behind them. Each result is a ready [signature](https://publicwww.com/docs/signatures/) - one click searches for it.

## How to run it

On the [clusters page](https://publicwww.com/profile/clusters/), upload a list of websites and press the fingerprint icon in the row of the cluster. The signatures page opens: it says which domains were looked at, and below them lists the signatures, best first.

An AI assistant can do the same through the [MCP tool](https://publicwww.com/docs/mcp/tools/) `build_signatures`, and then search for what it found.

## Reading the table

- **Signature** - the code itself, as it appears in the page source. Search for it as written: it is an exact phrase. When the code belongs to a technology we know, its name is shown next to it.
- **In the cluster** - how many of the websites looked at have this code.
- **Websites, approx.** - a rough count for the whole index. The search gives the exact number.
- **Search** - opens the results for the signature, ordered by popularity as any search.

## What works best

- **A cluster of websites that have something in common** - saved from one search, or a list of sites you know belong together: the customers of a product, the sites of one publisher, the shops on one platform.
- **A mixed cluster gives little.** When nothing ties the websites together, the page says so and lists nothing.
- **Check a signature before relying on it**, as any query: read the code under its results, at the start of the list and at the end - see [Checking a signature](https://publicwww.com/docs/signatures/checking/).

Building signatures is available on every account, the free one included, and does not use up searches or extraction points. Searching for a signature is an ordinary search.

Source: https://publicwww.com/docs/clusters/signatures/