Convert internationalized domain names (IDN) between Unicode form and ASCII Punycode (xn--) per RFC 3492, IDNA 2008, and UTS #46. Detects homograph attacks and mixed-script warnings.
Conversion
Per-label breakdown
Homograph / mixed-script analysis
How to Use Punycode / IDN Converter in 3 Steps
Configure. Paste a domain (Unicode or Punycode — auto-detected). The tool converts between forms following IDNA 2008 + UTS #46.
Process. Each label (subdomain piece) shows its own Unicode and Punycode form with any validation warnings.
Export. Mixed-script or homograph-risk domains are flagged with the confusable character highlighted — alerts you to potential phishing URLs.
Why Punycode / IDN Converter on Pixlane
Punycode encodes Unicode domain names as ASCII with the xn-- prefix — the only way DNS can carry non-English domains like münchen.de or 中国.cn. Pixlane uses the modern IDNA 2008 + UTS #46 processing rules (not the deprecated IDNA 2003), correctly handling case folding, disallowed characters, and contextual rules. Bonus: homograph detection flags domains with mixed Cyrillic/Latin characters — a common phishing tactic where аpple.com (with Cyrillic а) looks identical to apple.com.
IDNA 2008 + UTS #46 — Modern IDN processing per the 2010 RFC 5891 + Unicode Technical Standard #46. Handles contextual rules, case folding (ß → ss in IDNA 2008 non-transitional), and symbol restrictions.
Per-Label Conversion — DNS labels (subdomain pieces) are converted independently — each can mix ASCII and Unicode. Output is dot-joined for a complete domain.
Homograph Detection — Unicode Confusables database flags domains with characters that look like ASCII (Cyrillic а → a, Greek ο → o). Critical for spotting phishing URLs.
Bi-Directional — Paste Unicode to get Punycode, or paste Punycode to get Unicode back. Perfect for debugging email deliverability or SSL cert issues with IDN.
Frequently Asked Questions
Why does DNS need Punycode?
DNS was designed in the 1980s for ASCII only. When Unicode domains arrived in 2003 (IDN), existing DNS resolvers couldn't be upgraded at the protocol level. Punycode (RFC 3492) encodes Unicode into ASCII by placing the xn-- prefix on each label, so existing DNS infrastructure works unchanged.
What's the difference between IDNA 2003 and IDNA 2008?
IDNA 2003 folded ß → ss and σ → ς; IDNA 2008 preserves both (non-transitional mode). IDNA 2008 is the current standard, defined by RFC 5891. Most browsers now use UTS #46 transitional mode for backward compatibility during migration.
What is a homograph attack?
A phishing trick where attackers register a domain with Unicode characters that look identical to ASCII (e.g., Cyrillic а, Greek ο). аpple.com (with Cyrillic а) and apple.com are different domains but visually indistinguishable. Browsers mitigate by showing Punycode for mixed-script domains, but not always.
Is this tool free?
Yes. Punycode Converter on Pixlane is completely free with no signup required.