Rate Limits & Errors

Rate Limits

Rate limits are applied per account on a per-minute and per-day basis. Every plan has API access; limits vary by plan:

Plan	Requests / Minute	Requests / Day
Free	10	500
Pro	60	10,000
Advanced	120	50,000
Team	300	200,000
Enterprise	600	1,000,000

Daily windows reset at midnight UTC.

Creation Limits

Independent of request rates, new links and QR codes are capped per day. This pool is shared with your dashboard — creations from the U2L app and the API count against the same daily allowance:

Plan	New Links & QR Codes / Day
Free	50
Pro	500
Advanced	5,000
Team	5,000
Enterprise	10,000

Plans with unlimited links are subject to these fair-use velocity limits; total storage is not capped.

Rate Limit Headers

Every API response includes headers to help you track your rate limit usage:

Header	Description
X-RateLimit-Limit	Maximum requests per minute for your plan
X-RateLimit-Remaining	Remaining requests in the current minute window
X-RateLimit-Reset	Unix timestamp (seconds) when the rate limit resets
X-RateLimit-Daily-Limit	Maximum requests per day for your plan
X-RateLimit-Daily-Remaining	Remaining requests in the current UTC day

Example response headers

X-RateLimit-Limit: 60
X-RateLimit-Remaining: 54
X-RateLimit-Reset: 1707600060
X-RateLimit-Daily-Limit: 10000
X-RateLimit-Daily-Remaining: 9946

Rate Limit Exceeded

When you exceed a limit, the API returns a 429 Too Many Requests response with a Retry-After header and a machine-readable code — rate_limit_exceeded (minute window), daily_limit_exceeded (day window), or creation_limit_exceeded (daily creation cap):

{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Rate limit exceeded. Try again in 45 seconds.",
    "retryAfter": 45
  }
}

Error Response Format

All errors follow a consistent format with a machine-readable code and a human-readable message:

{
  "error": {
    "code": "error_code",
    "message": "Human-readable error message"
  }
}

Validation errors may include a details object with per-field error messages:

{
  "error": {
    "code": "validation_error",
    "message": "Invalid request body",
    "details": {
      "url": "Must be a valid URL",
      "tags": "Tags feature requires Pro plan or higher"
    }
  }
}

Error Codes

Status	Code	Description
400	bad_request	Invalid or missing request parameters
401	unauthorized	Missing or invalid API key
403	forbidden	Feature not available on your plan
404	not_found	Resource not found
409	conflict	Resource already exists (e.g., slug taken)
422	validation_error	Request body validation failed
429	rate_limit_exceeded	Too many requests this minute
429	daily_limit_exceeded	Daily request limit reached
429	creation_limit_exceeded	Daily link/QR creation limit reached
500	internal_error	Unexpected server error