A match pattern is a URL with the following structure, used to specify a group of URLs: ```text ://:/ ``` **scheme** : Must be one of the following, separated from the rest of the pattern using a colon followed by a double slash (`://`): - `http` - `https` - A wildcard `*`, which matches only `http` or `https` - `file` For information on injecting content scripts into unsupported schemes, such as `about:` and `data:`, see [Injecting in related frames](https://developer.chrome.com/docs/extensions/develop/concepts/content-scripts.md.txt#injecting-in-related-frames). **host** : A hostname (`www.example.com`). A `*` before the hostname to match subdomains (`*.example.com`), or just a wildcard `*`. - If you use a wildcard in the host pattern, it must be the first or only character, and it must be followed by a period (`.`) or forward slash (`/`). **port (optional)** : Port to match. By default, this is treated as a wildcard with the same behavior as `:*`. **path** : A URL path (`/example`). For host permissions, the path is required but ignored. The wildcard (`/*`) should be used by convention. Extensions use match patterns in a variety of use cases, including the following: - Injecting [content script](https://developer.chrome.com/docs/extensions/develop/concepts/content-scripts.md.txt). - [Declaring host permissions](https://developer.chrome.com/docs/extensions/develop/concepts/declare-permissions.md.txt#host-permissions) that some Chrome APIs require in addition to their own permissions. - Granting access to [web-accessible resources](https://developer.chrome.com/docs/extensions/reference/manifest/web-accessible-resources.md.txt#manifest-declaration). - Allowing message sending and receiving using the ["externally_connectable.matches"](https://developer.chrome.com/docs/extensions/reference/manifest/externally-connectable.md.txt#manifest) manifest key. ## Special cases `""` : Matches any URL that starts with a permitted scheme, including any pattern listed under [valid patterns](https://developer.chrome.com/docs/extensions/develop/concepts/match-patterns.md.txt#examples). Because it affects all hosts, Chrome web store reviews for extensions that use it [may take longer](https://developer.chrome.com/docs/webstore/review-process.md.txt#review-time-factors). `"file:///"` : Allows your extension to run on local files. This pattern requires the user to manually [grant access](https://developer.chrome.com/docs/extensions/develop/concepts/declare-permissions.md.txt#allow_access). Note that this case requires three slashes, not two. Localhost URLs and IP addresses : Use `http://localhost/*`, or `http://127.0.0.1/*` (to match an IP address). Match patterns match all ports unless an explicit port is specified. Top Level domain match patterns : Chrome doesn't support match patterns for [top Level domains (TLD)](https://developer.mozilla.org/docs/Glossary/TLD). Specify your match patterns within individual TLDs, as in `http://google.es/*` and `http://google.fr/*`. ## Example patterns `https://*/*` or `https://*/` : Matches any URL using the `https` scheme. `https://*/foo*` : Matches any URL using the `https` scheme, on any host, with a path that starts with `foo`. Examples of matches include `https://example.com/foo/bar.html` and `https://www.google.com/foo`. `https://*.google.com/foo*bar` : Matches any URL using the `https` scheme, on a google.com host, with a path that starts with `foo` and ends with `bar`. Examples of matches include `https://www.google.com/foo/baz/bar` and `https://docs.google.com/foobar`. `file:///foo*` : Matches any local file whose path starts with `foo`. Examples of matches include `file:///foo/bar.html` and `file:///foo`. `http://127.0.0.1/*` or `http://127.0.0.1/` : Matches any URL that uses the `http` scheme and is on the host 127.0.0.1. Examples of matches include `http://127.0.0.1/` and `http://127.0.0.1/foo/bar.html`. `http://localhost/*` : Matches any localhost port. `*://mail.google.com/` or `*://mail.google.com/*` : Matches any URL that starts with `http://mail.google.com` or `https://mail.google.com`.