Roblox Username Validate API — Check Username Availability (2026)

What Is the Roblox Username Validate Endpoint?

Roblox exposes a validation endpoint that reports whether a candidate username is acceptable. It is the same check Roblox runs during signup and username changes, so it is the most reliable signal of whether a name can be registered. The endpoint is:

Method	Endpoint
GET	`https://auth.roblox.com/v1/usernames/validate?request.username=NAME&request.birthday=2000-01-01`

It returns a JSON object with a numeric code and a human-readable message. The code tells you whether the name is valid and available, already taken, or rejected by the content filter.

Validate API Return Codes

Code	Meaning	Can you register it?
0	Username is valid and available	✅ Yes
1	Username is already taken	❌ No
2	Username is invalid / filtered (not allowed)	❌ No
10	Username was moderated (contains blocked content)	❌ No

💡 A code of 0 is the green light — the name passed Roblox's own validation and was available at the moment of the request.

Example Request (JavaScript / fetch)

A minimal read-only availability check. Add delays between calls to respect rate limits:

const url = "https://auth.roblox.com/v1/usernames/validate" +
  "?request.username=" + encodeURIComponent(name) +
  "&request.birthday=2000-01-01";
const res = await fetch(url);
const data = await res.json();
// data.code === 0 → available

Example Request (Python)

import requests, time
def is_available(name):
  u = "https://auth.roblox.com/v1/usernames/validate"
  p = {"request.username": name, "request.birthday": "2000-01-01"}
  r = requests.get(u, params=p, timeout=10)
  time.sleep(2)  # be polite to the rate limiter
  return r.json().get("code") == 0

Rate Limits & Terms of Service

Roblox throttles automated requests. Keep batches small (roughly 10–20 requests per minute), add delays between calls, and handle HTTP 429 (Too Many Requests) with a backoff. This information is for username research only — automated bulk account creation is prohibited by Roblox's Terms of Service. Always comply with the ToS.

The Easy Way: Generate + One-Click Check

You don't need to write any code to find available names. Our Roblox username generator produces uncommon, rules-compliant names by the batch, and every result has a 🔍 button that opens its Roblox profile page so you can verify availability in one click — no API keys, no rate limits, no setup.

Usernames Not Taken Rare Usernames 4-Letter Usernames

Roblox Username Validate API — Check Availability (2026)