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: ZenRows
providerId: zenrows
created: '2026-05-25'
modified: '2026-05-25'
reconciled: true
tags:
  - Web Scraping
  - Rate Limiting
  - Concurrency
description: ZenRows throttles by plan-level concurrency caps and by per-feature request budgets
  (Basic, JS Rendering, Premium Proxy, Protected). Quota exhaustion and concurrency overflow are
  both returned as 429 with distinct ZenRows error codes (AUTH008 vs AUTH006). Every successful
  response surfaces the current concurrency state in dedicated response headers, and 402 responses
  signal budget exhaustion before traffic is throttled. There is no documented per-second request
  ceiling beyond the concurrency cap.
sources:
  - https://www.zenrows.com/pricing
  - https://docs.zenrows.com/first-steps/pricing
  - https://docs.zenrows.com/api-error-codes
headers:
  concurrencyLimit: Concurrency-Limit
  concurrencyRemaining: Concurrency-Remaining
  requestCost: X-Request-Cost
  requestId: X-Request-Id
  finalUrl: Zr-Final-Url
responseCodes:
  concurrencyExceeded: 429
  rateLimited: 429
  quotaExceeded: 402
  featureNotInPlan: 402
  subscriptionInactive: 402
errorCodes:
  AUTH004: Plan usage exceeded
  AUTH006: Concurrency limit exceeded
  AUTH008: Rate limit exceeded
  AUTH010: Feature not included in plan
  AUTH011: No active subscription found
  AUTH012: Subscription does not allow product
limits:
  - name: Free Trial concurrency
    scope: account
    metric: concurrent_requests
    limit: 5
    notes: Applies during the $1 trial.
  - name: Developer concurrency
    scope: account
    metric: concurrent_requests
    limit: 20
    notes: Applies to the $69.99/mo Developer plan.
  - name: Startup concurrency
    scope: account
    metric: concurrent_requests
    limit: 50
    notes: Applies to the $129.99/mo Startup plan.
  - name: Business concurrency
    scope: account
    metric: concurrent_requests
    limit: 100
    notes: Applies to the $299.99/mo Business plan.
  - name: Business 500 concurrency
    scope: account
    metric: concurrent_requests
    limit: 150
    notes: Applies to the $499.99/mo Business 500 plan.
  - name: Business 1K–3K concurrency
    scope: account
    metric: concurrent_requests
    limit: 400
    notes: Applies to the Business 1K through Business 3K plans (up to 400 concurrent requests).
  - name: Enterprise concurrency
    scope: account
    metric: concurrent_requests
    limit: negotiated
    notes: Custom enterprise contracts negotiate concurrency above 400.
  - name: Basic requests quota
    scope: account
    metric: requests
    limit: plan-dependent
    notes: Monthly budget for plain requests (no js_render, no premium_proxy).
  - name: JS Rendering requests quota
    scope: account
    metric: requests
    limit: plan-dependent
    notes: Monthly budget for requests with js_render=true.
  - name: Premium Proxy requests quota
    scope: account
    metric: requests
    limit: plan-dependent
    notes: Monthly budget for requests with premium_proxy=true.
  - name: Protected requests quota
    scope: account
    metric: requests
    limit: plan-dependent
    notes: Monthly budget for requests against anti-bot-protected targets (mode=auto / Adaptive Stealth).
  - name: Max download size
    scope: per-response
    metric: megabytes
    limit: 5-20
    notes: Per-response size cap that scales with the plan (5 MB on Developer, 10 MB on Startup/Business/Trial, 20 MB on Business 500+).
policies:
  - name: Concurrency throttling
    description: Excess concurrent requests are rejected with 429 + AUTH006 rather than queued. Clients must monitor Concurrency-Remaining and back off.
  - name: Quota exhaustion
    description: When any of the four request budgets is depleted, requests return 402 + AUTH004. Quotas reset monthly.
  - name: Feature gating
    description: Calling a feature not included in the plan returns 402 + AUTH010 (e.g. premium_proxy on a no-premium plan).
  - name: Domain blocklist
    description: Certain domains are forbidden entirely (REQS001 / 400). Forbidden-sites policy is published separately.
  - name: Error-rate IP block
    description: BLK0001 (403) blocks a caller IP after sustained high error rates.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com