name: Subscan API Rate Limits
description: Rate limits enforced by the Subscan API service for accessing indexed Substrate blockchain data on Polkadot, Kusama, and related networks.
provider: Subscan
url: https://support.subscan.io/
contact: api@subscan.io
limits:
  - plan: Free
    rate:
      value: 5
      unit: requests/second
    daily:
      value: 100000
      unit: requests/day
    notes: Single API key allowed per account on the Free plan.
  - plan: Developer
    rate:
      value: null
      unit: requests/second
      notes: Rate limit not publicly disclosed; higher than Free plan.
    daily:
      value: 400000
      unit: requests/day
  - plan: Pro
    rate:
      value: null
      unit: requests/second
      notes: Custom rate limits available; contact api@subscan.io for details.
    daily:
      value: null
      unit: requests/day
      notes: Custom quotas negotiated per customer.
authentication:
  type: API Key
  header: X-API-Key
  registration: https://pro.subscan.io/
enforcement:
  - All requests must be authenticated with an API key
  - Endpoints are HTTPS only
  - Exceeding limits returns HTTP 429 Too Many Requests
references:
  - url: https://support.subscan.io/
    description: Official Subscan API documentation
  - url: https://subscan.statuspage.io/
    description: Subscan service status page