About

What is Punycoder?

Punycoder converts internationalized domain names (IDNs) between Unicode and their ASCII Punycode form. It also includes a URL percent encoder, an ASCII reference, and a hosting comparison.

Features

Live conversion — Results update as you type
Free — No registration required
Web app — No download required

Use cases

Domain registration — Prepare the ASCII form of an internationalized domain name
System administration — Configure systems that require Punycode hostnames
Software development — Convert a domain name for an API that expects its ASCII form

Audience

Software developers — Who need to encode or decode internationalized domain names in their applications
System administrators — Who need to configure DNS or systems with Punycode domain names
Domain registrars & webmasters — Who work with internationalized domain registrations

Company behind

Punycoder is operated from Prague by Glueo, s.r.o., a company that runs online services and provides custom software development.

Updated: September 7, 2026