v1.0 is now live

Don't let users be @elonmusk

The complete solution for username validation. Filter brands, profanity, reserved words, and premium names with a single API call.

1k Free RequestsNo Credit CardUsage-based Pricing

Status

Reserved

Latency

~45ms
JSON Response
{
  "username": "paris",
  "isReserved": true,
  "isDeleted": false,
  "categories": [
    {
      "category": "city",
      "metadata": {
        "country": "FR"
      }
    }
  ]
}

Everything you need to manage identity

Stop building internal blacklists. Use the industry standard for username governance.

15+ Categories

Instantly identify brands, celebrities, cities, offensive terms, and system-reserved keywords.

Global Edge Network

Powered by Cloudflare Workers. 300+ edge locations ensure sub-100ms latency worldwide.

Metadata Enriched

Don't just get a boolean. Get context—Country codes, languages, and category IDs.

High Performance

Built on KV and D1 storage for blazing fast reads. P95 latency is consistently under 300ms.

Smart Normalization

We handle case sensitivity, unicode characters, and whitespace automatically.

Best-in-class Security

Rate limiting, encrypted keys, and strict authentication standards out of the box.

What you can do with username.dev

Protect your namespace, automate moderation, and unlock new revenue — all through a single API.

Block restricted system terms

Stop users from claiming internal paths and sensitive roles like admin, root, support, and sysop.

Auto-moderate offensive usernames

Detect profanity, slurs, sexual content, and other abusive terms before they reach production.

Protect brands & identities

Identify brand names, franchises, celebrities, and city names to prevent impersonation and legal risk.

Monetize premium usernames

Flag short handles, dictionary words, and high-demand identifiers to support auctions or paid changes.

Stop maintaining blacklists.Let the API govern them for you

Built for modern platforms

If usernames matter to your product, this is for you.

Founders & product teams

Launching the next social network, marketplace, or community? Ship username governance on day one without building internal moderation tools.

Trust & Safety teams

Automate takedowns, impersonation defense, and profanity filtering at scale — without manual review.

Growth & revenue teams

Turn usernames into a paid feature: reservations, short-handle auctions, premium change fees, and more.

Drop-in integration for any stack

Stop maintaining massive regex lists and database tables. Integrate username.dev to manage that for you in minutes.

  • Universal compatibility (HTTP/JSON)
  • Type-safe responses
  • Built-in normalization
  • Latency < 200ms global average
curl -X GET "https://api.username.dev/check?input=paris" \
  -H "Authorization: Bearer un_live_xxx"

Prepaid Request Packs

No monthly fees. No subscriptions. Buy credits when you need them. Credits never expire.

Free Trial

1,000
Requests
$0
One-time
Start Free

Starter Pack

100,000
Requests
$10
$0.10 per 1k
Buy Starter
40% Savings

Pro Pack

500,000
Requests
$30
$0.06 per 1k
Best Value
Buy Pro
50% Savings

Scale Pack

2,000,000
Requests
$100
$0.05 per 1k
Buy Scale

Included in every pack

Regardless of which pack you choose, you get full access to our infrastructure and features.

Full API Category Access
Global Edge Network
Smart Normalization
Unlimited Latency Peaks
Email Support
Never Expiring Credits

Burning more than 10M requests per month?Get Enterprise Volume Pricing