Punycode & IDN Domain Converter
Punycode & IDN Domain Converter: Converts dot-separated IDN labels between Unicode and canonical ACE `xn--` forms without DNS resolution.
About this punycode & idn domain converter
Punycode & IDN Domain Converter — browser-based utility.
How this tool works
Converts dot-separated IDN labels between Unicode and the ACE `xn--` form. Unicode labels are normalized through the browser URL hostname parser; ACE labels are decoded only when they re-encode canonically. No DNS lookup is made.
- Paste a Unicode or `xn--` dot-separated label into “Input”.
- Click “Run locally”, then compare the converted label or explicit validation error in “Output”.
Worked example
Scenario: A network administrator decodes a canonical ACE IDN label without resolving a domain.
Sample input:
Processing: Decodes each ACE label, then requires canonical ACE re-encoding before returning Unicode; no DNS query is made.
Illustrative output:
Limits and verification
Input must be nonempty dot-separated text without surrounding or label whitespace. Empty labels, malformed ACE labels, and labels that fail canonical re-encoding are rejected. A final root dot is preserved. This is label conversion, not DNS resolution, registration lookup, or hostname-policy validation.
Examples demonstrate an expected workflow; they do not prove every input or every branch of an external specification. Check important results with an independent source before using them for money, security, compliance, safety, or irreversible file changes.
Browser processing boundary
Tool input is processed by code running in the browser and is not intentionally sent to a CZOA processing API. The page can still request ordinary site assets, analytics, or advertising when those services are enabled. Browser extensions and managed-device software remain outside this tool's control.
Relevant references
These references govern or help explain the format, protocol, or calculation used here. Listing a reference does not claim certification or complete implementation of every optional feature.
Content owner: CZOA Tools · Last reviewed: 2026-09-15 · Review methodology
How to use it
- Paste a Unicode or `xn--` dot-separated label into “Input”.
- Click “Run locally”, then compare the converted label or explicit validation error in “Output”.
Frequently asked questions
What does Punycode Converter transform?+
It converts IDN labels between xn-- ASCII representation and Unicode domain spelling.
What did the browser fixture verify?+
xn--bcher-kva.example returned bücher.example.
Does it validate a live domain?+
No. Label transformation does not resolve DNS, check registration, or assess hostname policy.
How are multiple labels handled?+
The implementation processes dot-separated labels and leaves the result subject to the current URL/IDN parser behavior.