Contifield

Text and developer tools

Punycode and IDN domain converter

Convert an internationalized domain between Unicode and ASCII Punycode with browser URL processing and round-trip validation.

Runs in your browser. Inputs stay on this page and are not uploaded or added to the URL.

Enter a domain only, in Unicode or ASCII. Do not include https://, an email address, a port or a path.

How to use this tool

The tool shows both the ASCII domain and the corresponding Unicode domain. Encoding uses the browser’s WHATWG URL domain processing with UTS #46; decoding applies RFC 3492 and checks that the Unicode result maps back to the same ASCII domain. This is a domain-name converter, not a raw Punycode text codec.

Domain labels are limited to 63 ASCII characters and the domain to 253 characters, excluding a final root dot. Mapping can normalize case, dots and equivalent forms. The tool makes no DNS lookup, ownership check or phishing assessment; visually similar Unicode characters can identify different domains.

Worked example

bücher.example ↔ xn--bcher-kva.example

References and method

Contifield is an independent utility site. Reference publishers do not endorse this tool.

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