Introduction
Prospects often ask the same question after opening the pricing page: “Why do Pro and Scale show a max requests per month, while Mega and Atlas say unlimited — but still show a large number with an asterisk?”
Those are not two marketing styles for the same thing. They are two different commercial contracts:
- Fixed-quota plans (Basic, Pro, Ultra, Scale) — you buy a monthly allowance of API requests, plus a rate limit that shapes how fast you can spend that allowance.
- Unlimited plans (Mega, Giga, Tera, Atlas) — there is no monthly request ceiling. What you buy is primarily throughput: a higher
req/minceiling for sustained pipelines.
This article is the buyer’s map. It is not a retry cookbook — for HTTP 429 handling in code, see rate limits and retries. Here we explain what you are paying for.
Two Limits, Two Jobs
Every plan exposes both concepts. Confusing them is the #1 source of wrong upgrades.
| Limit | Answers | Resets / applies | Typical failure mode |
|---|---|---|---|
| Monthly quota | How many requests can I send this billing period? | Resets with your billing cycle | Hard stop after the last credited request (HTTP 429 until reset or upgrade) |
| Rate limit (RPM) | How fast can I send requests right now? | Sliding per-minute window | Temporary 429 if you burst above your plan’sreq/min |
Fixed Quota Plans: You Pay for a Monthly Cap
Basic, Pro, Ultra and Scale are strong fixed-quota | plans. The monthly number on the pricing table is a real ceiling — not a soft estimate.
- Basic (free) — 1,000 requests/month, 20 req/min. Enough to integrate and ship a small feature without a card.
- Pro — typically 30,000 requests/month at 40 req/min. Common fit for SaaS onboarding checks and nightly portfolio jobs.
- Ultra — typically 150,000 requests/month at 60 req/min. For heavier enrichment or multi-endpoint pipelines.
- Scale — typically 1,000,000 requests/month at 100 req/min. Last fixed step before unlimited throughput plans.
Exact live numbers are always on /pricing (USD/EUR, monthly or yearly). Use that page as source of truth when you subscribe.
Why a hard monthly max exists
Fixed quotas keep cost predictable for both sides. You know the worst-case bill for the month. We can size cache, upstream WHOIS/RDAP capacity and support load around known envelopes. When you hit the cap, the API returns HTTP 429 until the cycle resets — or you upgrade and the higher quota applies immediately.
req/min causes short-lived 429s. Quota answers “how many this month”; RPM answers “how fast right now.”Unlimited Plans: You Pay for Rate Limit (Throughput)
Mega, Giga, Tera and Atlas are strong unlimited monthly quota | plans. There is no “you’ve used 100% of your monthly requests” wall. The commercial control is the rate limit: how many requests per minute your key may sustain.
- Mega — unlimited quota, typically 100 req/min (popular entry to unlimited).
- Giga / Tera — unlimited quota with higher RPM for continuous enrichment and large fleets.
- Atlas — unlimited quota at up to 900 req/min for maximum sustained throughput.
Why “unlimited” still shows a big monthly number*
On the pricing tables you will see something like “∞ Unlimited” plus a secondary line such as~3,456,000*. That asterisk number is not a hard cap. It is an estimate of how many requests you could theoretically send if you ran at about 80% of your rate limit, continuously, 24/7 for 30 days:
~max ≈ rateLimit × 60 × 24 × 30 × 0.8Example intuition: at 100 req/min, 80% sustained ≈ 80 requests every minute ≈ millions per month if you never stop. Most customers never run flat-out 24/7 — the estimate simply shows the headroom your RPM purchase unlocks.
Why WhoisJSON Offers Both Models
| Workload | Better model | Why |
|---|---|---|
| Prototypes, plugins, low monthly volume | Fixed quota (Basic → Scale) | Predictable cost; you may never need millions of calls |
| Steady SaaS feature with known monthly volume | Fixed quota sized above peak month | Simple budgeting; upgrade whenRemaining-Requests trends low |
| Continuous scanners, IOC enrichment, large ASM | Unlimited + higher RPM | Monthly volume is unbounded; the bottleneck is speed |
| Occasional huge one-off audits | Fixed high quota or short unlimited burst via upgrade | Prefer quota if the spike is rare; prefer RPM if audits repeat weekly |
In short: if your pain is “we run out of requests before month-end,” raise quota (or move to unlimited). If your pain is “jobs are too slow / too many 429s per minute while quota remains,” raise rate limit.
How to Choose in Practice
- Estimate monthly calls. Count domains × lookups per domain × runs per month. Remember multi-endpoint workflows (WHOIS + DNS + SSL = 3 credits per enriched domain).
- Estimate peak concurrency. How many parallel workers do you need for an acceptable job duration? That drives RPM more than monthly total.
- Start on the smallest plan that clears both numbers — use the calculator on the pricing page.
- Watch
Remaining-Requestson fixed plans and 429 frequency on all plans. Upgrade when either becomes a product risk.
_forceRefresh=1) costs 2 credits on eligible plans. High force-refresh rates consume fixed quotas twice as fast — see the caching guide.What HTTP 429 Means on Each Model
- Fixed quota exhausted — 429 until the billing cycle resets or you upgrade. Waiting a few seconds will not help; the monthly allowance is gone.
- Rate limit exceeded — 429 for the current minute window. Back off, lower concurrency, retry. Quota (if any) is unchanged.
Production clients should treat these differently in metrics and runbooks. Implementation patterns live in the 429 retries guide.
FAQ
What is the difference between quota and rate limit?
Quota is how many API requests you may send in a billing period. Rate limit is how many you may send per minute. Fixed plans enforce both; unlimited plans remove the monthly quota and keep the rate limit as the main control.
Are unlimited plans really unlimited?
There is no hard monthly request ceiling. You can keep calling the API all month as long as you respect the plan’s req/min limit and the terms of service. Fair-use and abuse protections still apply.
What does the “~max requests / month *” number mean on Mega and above?
It is an estimate: about 80% of your rate limit, sustained 24/7 for 30 days. It illustrates throughput headroom. It is not a billed cap.
Which plan should I pick if I only need 20,000 requests per month?
A fixed-quota plan such as Pro is usually enough. Unlimited plans make sense when monthly volume is high or unpredictable and you care about sustained speed. Always confirm on pricing.
Do all plans include the same endpoints?
Yes. Plan differences are quota, rate limit, monitoring slots and options such as force-refresh eligibility — not a locked feature menu per endpoint.
Can I upgrade mid-cycle?
Yes. Upgrades take effect immediately with the higher quota and rate limit. Downgrades apply at the next billing cycle.
Pick Quota or Throughput — Not Guesswork
Start free at 1,000 requests/month. Move to a fixed quota when volume is known. Move to Mega+ when you need unlimited volume bounded only by rate limit.
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