Convert between Unicode and Punycode for internationalized domain names (IDN).
Try it — live request, no key required
No key required to try it. Get a key to use it in your app.
{
"status": "ok",
"error": null,
"data": {
// Punycode Converter response payload
}
}
About the Punycode Converter API
Essential for working with international domain names containing non-ASCII characters like accents, Chinese, Arabic, or Cyrillic. It also detects homograph spoofing — flagging domain labels that mix writing systems (for example a Latin 'a' swapped for a visually identical Cyrillic one), the technique behind look-alike phishing domains.
What people use it for
- Domain Registration
- Verify and convert international domain names
- Web Development
- Handle IDN domains in applications
- Email Systems
- Process internationalized email addresses
- Security
- Detect homograph attacks using similar-looking Unicode characters
Ways to call it
One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.
- JSON
- Default REST response
- XML
- Markup format
- YAML
- Human-readable
- CSV
- Tabular export
- GraphQL
- Query language
- MCP
- For AI agents
Other ways to use Punycode Converter
Same data, same APIVerve account, same credit balance — one key works on all of them.
What does the Punycode Converter API do?
How do I authenticate Punycode Converter API requests?
How much does the Punycode Converter API cost?
How fast is the Punycode Converter API?
What response formats does the Punycode Converter API support?
What HTTP method does the Punycode Converter API use?
Request parameters — GET /v1/punycode
Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.
Required
| Parameter | Type | Example | Description |
|---|---|---|---|
textRequired | string | münchen.de | Unicode text or domain to encode (max 1000 characters) length 0-1000 |
Optional
| Parameter | Type | Example | Description |
|---|---|---|---|
modeOptional | string | encode | Conversion modeencodedecodedefault encode |
curl "https://api.apiverve.com/v1/punycode?text=m%C3%BCnchen.de&mode=encode" \
-H "x-api-key: YOUR_API_KEY"Authentication
Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.
| Header | When | Value |
|---|---|---|
x-api-keyRequired | Every request | Your API key. Header names are case-insensitive, so X-API-Key is the same header. |
AuthorizationAlternate | Instead of the above | Bearer <key> — for clients that only expose bearer auth. Resolves to the same account and the same billing. |
A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.
Response — GET /v1/punycode
Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.
{
"status": "ok",
"error": null,
"data": {
"input": "münchen.de",
"output": "xn--mnchen-3ya.de",
"mode": "encode",
"isIDN": true,
"scripts": [
"Latin"
],
"mixedScript": false
}
}
Response fields
Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.
| Field | Type | Example | Description |
|---|---|---|---|
input | string | "münchen.de" | Original Unicode text provided for encoding conversion |
output | string | "xn--mnchen-3ya.de" | Converted Punycode text with xn-- prefix format |
mode | string | "encode" | Conversion mode used for the transformation operation |
isIDNPremium | boolean | true | Indicates if result is valid internationalized domain name |
scripts | array | [Latin] | Writing systems (Latin, Cyrillic, Greek, Han, etc.) detected in the domain's non-ASCII labels. Empty for a plain ASCII domain; a single entry for a legitimate international domain |
mixedScriptPremium | boolean | false | True when a single domain label mixes writing systems in a way no real language does (e.g. Latin combined with Cyrillic) — the signature of a homograph / look-alike phishing domain. Legitimate combinations such as Japanese (Han + Hiragana/Katakana) are not flagged. Detects cross-script spoofs, not same-script look-alikes |
Response headers
Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.
| Header | What it carries |
|---|---|
x-api-remaining-credits | Credits left in the current cycle |
x-api-credits-used | Credits spent in the current cycle |
x-api-max-credits | The allowance for the cycle |
x-api-version | Version of the endpoint that answered |
Errors
Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.
| Status | Meaning | What to do |
|---|---|---|
400 | Input was rejected | Read error; it names the parameter that has to change. |
401 | Key missing or invalid | Check the header name and the key value. |
403 | Key valid, but not permitted here | A key restriction or an IP allow-list — never a bad key. |
429 | Rate limited, or out of credits | Read error to tell them apart, then back off or top up. |
What a call costs — 2 credits per call
Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.
| Plan | Per month | Credits | Punycode Converter calls | Per 1,000 calls |
|---|---|---|---|---|
| Free | Free | 200 | 100 | Free |
| Starter | $29.99 | 200,000 | 100,000 | $0.30 |
| Pro | $99.99 | 1,000,000 | 500,000 | $0.20 |
| Mega | $299.99 | 4,000,000 | 2,000,000 | $0.15 |
Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.
Call it from cURL — GET /v1/punycode
No SDK to install — this is a plain HTTPS call to /v1/punycode with your key in the x-api-key header. Swap in a real key and it runs as-is.
curl "https://api.apiverve.com/v1/punycode" \
-H "x-api-key: YOUR_API_KEY"Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Node.js — GET /v1/punycode
Install the Node.js SDK, then call the Punycode Converter API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
npm install @apiverve/punycodeconst res = await fetch("https://api.apiverve.com/v1/punycode", {
headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Python — GET /v1/punycode
No SDK to install — this is a plain HTTPS call to /v1/punycode with your key in the x-api-key header. Swap in a real key and it runs as-is.
import requests
res = requests.get(
"https://api.apiverve.com/v1/punycode",
headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from C# / .NET — GET /v1/punycode
Install the C# / .NET SDK, then call the Punycode Converter API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
dotnet add package APIVerve.API.PunycodeConverterusing var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");
var json = await client.GetStringAsync("https://api.apiverve.com/v1/punycode");
Console.WriteLine(json);Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Go — GET /v1/punycode
No SDK to install — this is a plain HTTPS call to /v1/punycode with your key in the x-api-key header. Swap in a real key and it runs as-is.
req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/punycode", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from PHP — GET /v1/punycode
No SDK to install — this is a plain HTTPS call to /v1/punycode with your key in the x-api-key header. Swap in a real key and it runs as-is.
$ch = curl_init("https://api.apiverve.com/v1/punycode");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);
$response = curl_exec($ch);
echo $response;Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Ruby — GET /v1/punycode
No SDK to install — this is a plain HTTPS call to /v1/punycode with your key in the x-api-key header. Swap in a real key and it runs as-is.
require "net/http"
uri = URI("https://api.apiverve.com/v1/punycode")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"
res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.bodyResources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Zero-code embed — one snippet, no backend
Drop an interactive Punycode Converter form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.
Changelog — Punycode Converter API
Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.
Entries are picked up from dated catalog snapshots, so the first one appears after the next snapshot that moves something. A period where nothing changed produces no entry — silence is a valid changelog for the Punycode Converter API.
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