IDN Converter
Enter a domain in either form, such as a name written in Devanagari or its `xn--` equivalent. The converter shows both versions and checks the name for problems.
- Utilities
- Live check
- Free, no sign-up
- Results are not published
Run IDN Converter
At a glance
- What it checks
- Convert internationalized domain names between Unicode and Punycode (xn--) forms and spot mixed scripts.
- Data source
- The UTS #46 IDNA standard, run locally.
- Freshness
- Calculated on request, nothing is looked up
- Limits
- Converts names; it does not check whether they are registered. Methodology
- Cost
- Free, no account needed
Understanding the result
Why two forms exist
The DNS was designed for letters A to Z, digits and hyphens. Internationalized domain names (IDNs) allow other scripts, such as Devanagari, Arabic or Cyrillic, by encoding each non-ASCII label as ASCII using Punycode and adding the xn-- prefix. The readable version is called the U-label and the encoded version the A-label.
Browsers show the Unicode form where it is safe to do so, while DNS records, certificates and many configuration files need the A-label. This converter lets you move between them, for example when adding an IDN to a web server configuration or checking what a suspicious xn-- link really says.
How the conversion works
Conversion runs locally on DomainDNSCheck's server using the Unicode IDNA Compatibility Processing standard, UTS #46, in non-transitional mode. It applies the standard hostname character rules and the bidirectional and joiner checks required for scripts such as Arabic and Hebrew. No DNS queries are made, and the name is not looked up or registered anywhere.
Input is normalized first, so uppercase letters become lowercase and compatible characters are mapped to their standard forms. If a label contains characters that are not permitted, the converter reports the name as invalid rather than producing an unusable result.
Reading the result
The result shows the full name in both forms, followed by a table of labels with the ASCII and Unicode version of each, whether it is an IDN label and its length in bytes. Each label may be up to 63 bytes in its ASCII form.
- Scripts (INFO): the writing systems detected in the name.
- Mixed scripts (WARNING): the name combines Latin letters with another script. This is a classic technique for lookalike (homograph) domains, where a Cyrillic "а" replaces a Latin "a", for example. Mixed-script names can be legitimate, but check them carefully before trusting a link.
- Length (FAIL): the full ASCII name exceeds 253 characters, the maximum allowed in DNS.
Using IDNs in practice
Not every extension accepts every script, and registries set their own rules about which characters are allowed. Email addresses on IDN domains also need support from both the sending and receiving software. Once you have the A-label, you can use it with the DNS Lookup, Domain Availability and other tools on this site, which all accept either form. For background on country-code extensions, see What is a ccTLD?
Frequently asked questions
What is Punycode?
An algorithm that represents a string of Unicode characters using only ASCII letters, digits and hyphens. In domain names it is always combined with the xn-- prefix so software can recognize encoded labels.
Why does my browser show the xn-- form instead of the Unicode name?
Browsers display the encoded form when a name mixes scripts in a way that could be used for spoofing, or contains characters that are easily confused with others. Each browser applies its own rules, and the fallback is a deliberate safety measure.
Why do two different Unicode inputs give the same xn-- result?
UTS #46 maps equivalent characters to a single form before encoding, for example uppercase to lowercase and full-width letters to regular ones. Both inputs therefore refer to the same domain.
Is the name I enter sent anywhere?
No lookups are performed. The conversion is a local calculation, and nothing is sent to registries or DNS resolvers.