--- title: safeURL description: Declares the provided string as a safe URL or URL substring. keywords: [strings,urls] categories: [functions] menu: docs: parent: functions signature: ["safeURL INPUT"] relatedfuncs: [] --- `safeURL` declares the provided string as a "safe" URL or URL substring (see [RFC 3986]). A URL like `javascript:checkThatFormNotEditedBeforeLeavingPage()` from a trusted source should go in the page, but by default dynamic `javascript:` URLs are filtered out since they are a frequently exploited injection vector. Without `safeURL`, only the URI schemes `http:`, `https:` and `mailto:` are considered safe by Go templates. If any other URI schemes (e.g., `irc:` and `javascript:`) are detected, the whole URL will be replaced with `#ZgotmplZ`. This is to "defang" any potential attack in the URL by rendering it useless. The following examples use a [site `config.toml`][configuration] with the following [menu entry][menus]: {{< code-toggle file="config" copy=false >}} [[menu.main]] name = "IRC: #golang at freenode" url = "irc://irc.freenode.net/#golang" {{< /code-toggle >}} The following is an example of a sidebar partial that may be used in conjunction with the preceding front matter example: {{< code file="layouts/partials/bad-url-sidebar-menu.html" copy=false >}} {{< /code >}} This partial would produce the following HTML output: ```html ``` The odd output can be remedied by adding ` | safeURL` to our `.URL` page variable: {{< code file="layouts/partials/correct-url-sidebar-menu.html" copy=false >}} {{< /code >}} With the `.URL` page variable piped through `safeURL`, we get the desired output: ```html ``` [configuration]: /getting-started/configuration/ [menus]: /content-management/menus/ [RFC 3986]: https://tools.ietf.org/html/rfc3986