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: Flickr
providerId: flickr
created: '2026-05-30'
modified: '2026-05-30'
reconciled: false
tags:
  - Rate Limiting
  - Photography
  - Photos
  - Developer API
description: >-
  Flickr enforces request-rate throttling per API key. Limits are not aggressively
  published, but the long-standing documented guideline is 3,600 queries per hour
  per non-commercial API key, with commercial keys reviewed and adjusted on a
  case-by-case basis. Excessive request rates can result in the key being
  temporarily or permanently throttled. There is no formal sandbox environment;
  all calls hit api.flickr.com. Burst patterns and abusive usage are addressed
  via Flickr's API Terms of Use, not via a public rate-limit HTTP header.
sources:
  - https://www.flickr.com/services/api/
  - https://www.flickr.com/services/api/tos/
  - https://www.flickr.com/services/developer/
  - https://www.flickr.com/services/api/misc.api_keys.html
responseCodes:
  throttled: 429
  throttledLegacy: 503
  invalidKey: 100
  badRequest: 105
limits:
  - name: Per-key queries per hour (non-commercial)
    scope: key
    metric: requests_per_hour
    limit: 3600
    timeFrame: hour
    notes: >-
      Long-standing documented guideline for non-commercial keys. Flickr may
      temporarily throttle keys that exceed this; sustained abuse can revoke
      the key.
  - name: Per-key queries per second (burst)
    scope: key
    metric: requests_per_second
    limit: 1
    timeFrame: second
    notes: >-
      Practical burst guidance derived from the per-hour limit; Flickr does
      not publish a hard per-second number.
  - name: Per-key queries per hour (commercial)
    scope: key
    metric: requests_per_hour
    limit: 'negotiated with Flickr'
    notes: >-
      Commercial keys may have a higher ceiling; the exact number is set
      during the commercial review process.
  - name: Photo upload throughput
    scope: key
    metric: varies
    limit: 'subject to per-key hourly cap and per-file size limits'
    notes: >-
      Uploads count against the per-key hourly cap. Per-file size caps are
      enforced at the upload endpoint (`https://up.flickr.com/services/upload`).
policies:
  - name: Exponential backoff
    description: >-
      Clients receiving a 429 or 503 should back off exponentially before
      retrying. Flickr does not publish a specific backoff curve; treat 503
      as a transient-throttling signal.
  - name: One key per application
    description: >-
      Each distinct application MUST use its own API key. Sharing keys
      between applications is grounds for revocation and skews
      per-key throttling decisions.
  - name: Identify your app
    description: >-
      Flickr's TOS asks that all requests include identifying parameters
      (the API key, optionally a User-Agent that names your application)
      so abusive callers can be isolated without affecting compliant ones.
  - name: Commercial use requires permission
    description: >-
      Any commercial use of the API requires a commercial API key approved
      by Flickr. Throttling and quota terms for commercial keys are
      negotiated as part of approval.
  - name: No public quota / remaining headers
    description: >-
      Flickr does not document `X-RateLimit-*` style response headers.
      Clients should track their own request rates locally rather than
      relying on server-returned remaining-quota signals.
  - name: Push subscriptions vs polling
    description: >-
      For change-driven workloads, prefer the PubSubHubbub push API
      (`flickr.push.*`) over high-frequency polling — push subscriptions
      do not count toward the per-key hourly cap once established.