Punycode (RFC 3492) is a way to encode Unicode strings into the limited ASCII character set allowed by the Domain Name System. Domain labels that contain non-ASCII characters are prefixed with "xn--" to indicate ACE encoding.

What is an internationalized domain name (IDN)?

An IDN is a domain name that contains characters outside the basic ASCII set, such as Arabic, Chinese, Cyrillic, or accented Latin letters. Browsers display the Unicode form but DNS resolvers use the Punycode-encoded form.

Is my data sent to a server?

No. All encoding and decoding runs locally in your browser using JavaScript. Nothing is transmitted anywhere.

Why does only part of the domain get encoded?

Each label (segment between dots) is encoded independently. Pure-ASCII labels — including most TLDs like .com or .org — are left unchanged. Only labels containing non-ASCII characters receive the xn-- prefix.

What happens if I enter an invalid Punycode string?

The tool shows an inline error message describing the problem. Common causes include malformed xn-- labels or characters outside the allowed Unicode ranges.

Can I encode an entire URL, not just a hostname?

This tool processes the hostname portion only. Strip the scheme (https://) and path before pasting if you want to convert just the domain labels.

Punycode Decoder

Convert Punycode-encoded domain names (xn--...) to Unicode and back instantly in your browser.

Input Domain

Enter a Punycode (xn--...) or Unicode domain name.

Quick Examples

Result

Label Breakdown

Run a conversion to see the per-label details.

About Punycode

Punycode (RFC 3492) encodes Unicode labels into ASCII using a xn-- prefix followed by ASCII characters and a hyphen-separated encoding suffix. Only labels containing non-ASCII code points are encoded — pure-ASCII labels like .com stay unchanged.

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Summary

Punycode is an encoding system defined in RFC 3492 that represents Unicode domain names using only ASCII characters. Internationalized domain names (IDN) use Punycode to support characters from non-Latin scripts, making them compatible with the DNS system. This tool converts between the human-readable Unicode form and the ASCII-compatible encoding (ACE) form prefixed with xn--.

How it works

Paste a Punycode domain (e.g. xn--nxasmq6b.com) or a Unicode domain (e.g. παράδειγμα.com) into the input.
The tool auto-detects whether the input is Punycode or Unicode.
Click Decode to convert Punycode labels to Unicode, or Encode to convert Unicode to Punycode.
Each domain label is processed independently — the TLD and pure-ASCII labels remain unchanged.
Copy the result with the Copy button or swap it back into the input for round-trip testing.

Use cases

Decode internationalized domain names received in emails or logs.
Verify that your IDN domain encodes correctly before registering it.
Debug DNS records that show xn-- prefixed labels.
Convert Unicode hostnames to ASCII-compatible form for use in configuration files.
Teach yourself how Punycode encodes non-ASCII characters.
Spot homograph phishing attacks by decoding lookalike domains.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu