Golang HTML Sanitizer / Filter

htmlsanitizer is a super fast, allowlist-based HTML sanitizer (HTML filter) written in Golang. A built-in, secure-by-default allowlist helps you filter out any dangerous HTML content.

Why use htmlsanitizer?

• Fast, a Finite State Machine was implemented internally, making the time complexity always O(n).
• Highly customizable, allows you to modify the allowlist, or simply disable all HTML tags.
• Dependency free.

Install

go get -u github.com/sym01/htmlsanitizer

Getting Started

Use the secure-by-default allowlist

Simply use the secure-by-default allowlist to sanitize untrusted HTML.

sanitizedHTML, err := htmlsanitizer.SanitizeString(rawHTML)

Disable the id attribute globally

By default, htmlsanitizer allows the id attribute globally. If we do NOT allow the id attribute, we can simply override the GlobalAttr.

s := htmlsanitizer.NewHTMLSanitizer()
s.GlobalAttr = []string{"class"}

sanitizedHTML, err := s.SanitizeString(rawHTML)

Disable or add HTML tag

s := htmlsanitizer.NewHTMLSanitizer()
// remove <a> tag
s.RemoveTag("a")

// add a custom tag named my-tag, which allows my-attr attribute
customTag := &htmlsanitizer.Tag{
    Name: "my-tag",
    Attr: []string{"my-attr"},
}
s.AllowList.Tags = append(s.AllowList.Tags, customTag)

sanitizedHTML, err := s.SanitizeString(rawHTML)

Disable all HTML tags

You can also use htmlsanitizer to remove all HTML tags.

s := htmlsanitizer.NewHTMLSanitizer()
// just set AllowList to nil to disable all tags
s.AllowList = nil

sanitizedHTML, err := s.SanitizeString(rawHTML)