specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: Last.fm
providerId: lastfm
created: '2026-05-29'
modified: '2026-05-29'
tags:
  - Music
  - Scrobbling
  - Rate Limiting
  - Throttling
description: >-
  Last.fm enforces rate limits at the originating IP / API key level. The
  documented guidance is approximately 5 requests per second per originating IP.
  Sustained excess yields account suspension. The API does not publish standard
  RFC 9239 RateLimit headers and instead returns numeric Last.fm error codes
  (notably code 29 — Rate limit exceeded — and code 26 — Suspended API key).
  Scrobble batches are hard-capped at 50 scrobbles per request.
headers:
  limit: null
  remaining: null
  reset: null
  retryAfter: Retry-After
  policy: null
responseCodes:
  throttled: 429
  quotaExceeded: 403
  serviceUnavailable: 503
errorCodes:
  rateLimitExceeded: 29
  suspendedApiKey: 26
  serviceTemporarilyUnavailable: 16
  invalidApiKey: 10
  invalidMethodSignature: 13
limits:
  - tier: free
    name: Per-Origin Rate Guidance
    scope: originating-ip
    metric: requests_per_second
    limit: 5
    burst: 10
    timeFrame: second
    applies:
      - Last.fm Web Services 2.0
    notes: >-
      "Your account may be suspended if your application is continuously making
      several calls per second or if you're making excessive calls."
      (from www.last.fm/api/intro)
  - tier: free
    name: Scrobble Batch Cap
    scope: api-key
    metric: scrobbles_per_request
    limit: 50
    timeFrame: request
    applies:
      - track.scrobble
    notes: A single track.scrobble call may carry at most 50 scrobbles.
  - tier: free
    name: Reasonable Usage Cap
    scope: api-key
    metric: bytes_total
    limit: 104857600
    timeFrame: total
    applies:
      - All methods (data storage by consumer)
    notes: From Terms of Service — 100 MB total stored Last.fm Data per integration.
  - tier: commercial
    name: Commercial Agreement Negotiated Rate
    scope: api-key
    metric: requests_per_second
    limit: 0
    timeFrame: second
    applies:
      - Last.fm Web Services 2.0
    notes: >-
      Higher rates available only under a commercial agreement — contact
      partners@last.fm.
recommendations:
  - identify your client with a descriptive User-Agent header
  - back off on HTTP 503 and on Last.fm error codes 16 (temporarily unavailable) and 29 (rate limited)
  - avoid bursting requests on page load — defer and cache results
  - cache long-lived metadata (artist.getInfo, album.getInfo, tag.getInfo) aggressively
  - resend scrobbles after connection failure via batched track.scrobble (up to 50)