Tools Home

Punycode & IDN Domain Converter (RFC 3492 & Spoofing Detector)

Convert internationalized domain names (IDN) bidirectionally between Unicode and ASCII Punycode (xn--) with built-in homograph attack and script spoofing analysis.

Presets:
Input Domain / URL32 chars
Converted Domain
https://xn--mnchen-3ya.de/kultur/events
Character Codepoint Analysis (32 characters)
GlyphCode PointScript CategorySecurity Notice
hU+0068Latin (ASCII)Normal
tU+0074Latin (ASCII)Normal
tU+0074Latin (ASCII)Normal
pU+0070Latin (ASCII)Normal
sU+0073Latin (ASCII)Normal
:U+003ALatin (ASCII)Normal
/U+002FLatin (ASCII)Normal
/U+002FLatin (ASCII)Normal
mU+006DLatin (ASCII)Normal
üU+00FCLatin ExtendedNormal
nU+006ELatin (ASCII)Normal
cU+0063Latin (ASCII)Normal
hU+0068Latin (ASCII)Normal
eU+0065Latin (ASCII)Normal
nU+006ELatin (ASCII)Normal
.U+002ELatin (ASCII)Normal
dU+0064Latin (ASCII)Normal
eU+0065Latin (ASCII)Normal
/U+002FLatin (ASCII)Normal
kU+006BLatin (ASCII)Normal
uU+0075Latin (ASCII)Normal
lU+006CLatin (ASCII)Normal
tU+0074Latin (ASCII)Normal
uU+0075Latin (ASCII)Normal
rU+0072Latin (ASCII)Normal
/U+002FLatin (ASCII)Normal
eU+0065Latin (ASCII)Normal
vU+0076Latin (ASCII)Normal
eU+0065Latin (ASCII)Normal
nU+006ELatin (ASCII)Normal
tU+0074Latin (ASCII)Normal
sU+0073Latin (ASCII)Normal
Unicode Length32
Punycode Length39
RFC StandardRFC 3492
Security HealthClean

100% Client-Side Privacy

Your domain names and confidential intranet URLs are processed purely in local browser memory without querying third-party APIs.

RFC 3492 / IDNA 2008 Parity

Full algorithmic compliance for encoding Unicode code points into ASCII Compatible Encoding (ACE) with the standard 'xn--' label prefix.

Homoglyph Spoofing Audit

Deep character inspector flags lookalike Cyrillic and Greek characters that attackers use to create deceptive phishing URLs.

Technical Reference & Architecture Guide

Punycode & IDN Domain Converter Developer Guide — Reference Guide

Complete RFC 3492 and RFC 5891 reference for encoding and decoding Internationalized Domain Names (IDN) with homograph spoofing detection.

Key Parameters & Controls

inputModestring ('encode' | 'decode')

Conversion direction: Unicode to ASCII Punycode (xn--) or vice versa.

preserveSchemeboolean

Retain URL protocol prefixes (http://, https://) and path parameters.

homographAuditboolean

Scan domain labels for mixed-script spoofing and lookalike characters.

unicodeNormalizationstring ('NFC')

Canonical Unicode normalization applied to domain labels prior to Punycode encoding.

Pro Tips & Best Practices

Always inspect the Punycode equivalent of incoming domains to detect phishing attacks impersonating financial brands with Cyrillic characters.

SSL/TLS certificates for internationalized domains are issued to the ASCII Punycode form (e.g., xn--...-3ya.de).

DNS resolvers operate exclusively on ASCII strings; IDNs must be converted to Punycode before querying nameservers.

Common Gotchas & Troubleshooting

IDNA 2008 restricts emoji domain registration. Ensure inputs conform to RFC 5891 label validation rules.

Mixed-script warnings occur when Latin and non-Latin alphabets appear within the same domain label.

Frequently Asked Questions

What is the xn-- prefix in domain names?▼

The 'xn--' prefix is an ACE (ASCII Compatible Encoding) indicator indicating that the label contains Punycode-encoded Unicode characters.

What is an IDN homograph attack?▼

It is a deception technique where an attacker registers a domain using Cyrillic or Greek letters that look identical to Latin letters to mimic a legitimate website.

Does this tool work with full URLs?▼

Yes. It extracts the hostname portion of the URL, converts it, and reconstructs the full URL.

Is my domain input logged or inspected externally?▼

No. All RFC 3492 algorithm operations run locally in your browser.

Related Tools & Utilities

All Tools →
Raw HTTP Header Parser & Cache/Security Inspectorsecurity

Parse raw HTTP request and response headers into structured key-value tables, inspect Cache-Control directives, evaluate security posture, and decode Set-Cookie tokens.

Open tool→
EFF Diceware Passphrase Generator (Shannon Entropy & Crack Time)security

Generate cryptographically secure, memorable multi-word passphrases using EFF Diceware wordlists, custom delimiters, number injection, and instant Shannon entropy calculation.

Open tool→
JWT Token Decoder & Security Inspectorsecurity

Decode JSON Web Tokens, inspect header/payload claims, calculate expiration time and verify integrity locally.

Open tool→
Cryptographically Secure Password Generatorsecurity

Generate ultra-secure passwords using Web Crypto API with custom length, symbols, and memorability.

Open tool→
Multi-Algorithm Hash Generator (SHA-256, SHA-512, MD5)security

Compute instant cryptographic hashes entirely in browser with zero server transmission.

Open tool→
JSON Web Token (JWT) Debugger & Signature Verifiersecurity

Decode, verify, and inspect JWT headers, payloads, and claims with local secret or public key without sending data to servers.

Open tool→