v148 · Security · IDN

Domain Validator

Enter an internationalized domain name and see whether it passes IDNA2008 ContextJ rules as enforced by Chrome 148. The validator identifies Zero Width Joiner (ZWJ) and Zero Width Non-Joiner (ZWNJ) characters and explains whether their Unicode joining context is valid.

Enter a domain name above and click Validate.

Sample domains — click to test

What ContextJ rules check

// Zero Width Non-Joiner (U+200C) is valid ONLY when:
//   1. Preceded by a Virama (e.g. Devanagari ् U+094D), or
//   2. Between two characters that are "Dual Joining" or "Left/Right Joining"
//      and separated by characters in the "Transparent" joining class

// Zero Width Joiner (U+200D) is valid ONLY when:
//   1. Preceded by a Virama

// Chrome 148 now enforces these rules in URL parsing
// A domain like "exam‌ple.com" is VALID only in the right script context
// In ASCII context it fails and the URL becomes an error URL

references

implementation reference

Need the exact API surface, compatibility boundaries, errors, lifecycle, and source links? Read the matching gendn reference ↗