Username governance
Filter brands, profanity, reserved words, and premium names with a single API call. Stop maintaining blacklists and internal moderation tools—let the API govern usernames for you.Why username.dev?
15+ Categories
Instantly identify brands, celebrities, cities, offensive terms, system-reserved keywords, and more.
Global Edge Network
Powered by Cloudflare Workers with sub-100ms latency worldwide. 300+ edge locations ensure fast responses.
Smart Normalization
Automatic handling of case sensitivity, unicode characters, and whitespace. You focus on your app, we handle the complexity.
1,000 Free Requests
Get started immediately with 1,000 free requests. No credit card required. Credits never expire.
What’s next?
- Quick start guide - Get up and running in minutes with your first API call
- Check endpoint documentation - Learn all the details about the
/checkendpoint - Error codes - Understand error responses and how to handle them
- Troubleshooting - Common troubleshooting tips and solutions
- Get your API key - Sign up and start using the API
Rate limits
All API keys have a rate limit of 5 requests per second. If you exceed this limit, you’ll receive a429 response with a retryAfter field indicating when to retry. For high-volume use cases, contact us for enterprise rate limit options.
Username normalization
All usernames are automatically normalized before checking:- Remove all whitespace -
"new york"→"newyork" - Convert to lowercase -
"Paris"→"paris" - Preserve hyphens/underscores -
"new-york"stays"new-york" - Preserve special characters -
"café"stays"café"(Unicode supported)
Username normalization happens automatically on the server. You don’t need to pre-process usernames before sending them to the API.