Question 1

What is Punycode?

Accepted Answer

Punycode is an encoding system that converts Unicode strings (like Chinese, Arabic, or emoji) into the limited ASCII character set used by DNS. Internationalized domain names are encoded as xn-- prefixed ASCII strings.

Question 2

What is an IDN (Internationalized Domain Name)?

Accepted Answer

An IDN is a domain name that contains Unicode characters (non-ASCII) such as 中文.com, москва.ru, or 日本.jp. These are stored in DNS as Punycode (xn--) but displayed in browsers as Unicode.

Question 3

Why do domains need Punycode encoding?

Accepted Answer

The DNS system only supports ASCII characters. Internationalized Domain Names (IDNs) are encoded using Punycode, prefixed with xn--.

For example: 例子.com → xn--fsq092h.com

Each label (segment between dots) is independently encoded. ASCII-only labels are left unchanged.

Question 4

What does the xn-- prefix mean?

Accepted Answer

The 'xn--' prefix (called ACE prefix) identifies a Punycode-encoded label in DNS. When you see xn--nxasmq6b.com, it's the Punycode form of a Unicode domain. Browsers automatically convert these for display.

Question 5

Can I convert entire URLs or just domain names?

Accepted Answer

This tool converts domain names. For full URLs, only the domain portion is converted. For example, https://例子.测试/path would have its domain (例子.测试) converted while the path remains unchanged.

Question 6

Does this tool support emoji domains?

Accepted Answer

Yes. Emoji and other special Unicode characters can be converted to Punycode. For example, 🌐.com can be encoded to its Punycode equivalent.

Question 7

Are Punycode conversions reversible?

Accepted Answer

Yes, Punycode encoding and decoding are lossless and fully reversible. Converting Unicode to Punycode and back always produces the original string.

Question 8

How does Punycode handle homograph attacks?

Accepted Answer

Punycode can be used to detect homograph attacks where lookalike characters from different scripts are mixed. Converting suspicious domains to Punycode reveals their true characters, helping identify phishing attempts.

Punycode / IDN Converter

Conversion Results

How It Works

Related Tools