Rate Limiter Calculator

Compute rate limiting parameters and conversions.

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Input
Output
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About rate limiter calculator

Rate Limiter Calculator needs nothing from a server once the page has loaded. Leave it open on a train with no signal and it carries on.

Everything runs client side, which is the only arrangement where a privacy claim is checkable. Open the network tab and watch it stay empty.

You will find it under Schedules, alongside 7 other tools for the same sort of job.

Shows requests per second/minute/hour, token bucket, and sliding window analysis.

How to use it

01
Start it
Every control is on the tool itself. Keyboard shortcuts, where there are any, are listed beside it.
02
Watch it run
It updates in the page as you go. Nothing is sent anywhere, so it keeps working with the network off.
03
Close when done
Nothing is stored between visits. Reloading gives you a clean start rather than picking up where you left off.

Examples

API Rate Limit
Calculate rate limiting for 100 requests per minute with burst of 10
Input
requests: 100
windowSeconds: 60
burstSize: 10
Output
=== Rate Limit Calculator ===

Configuration:
  Requests: 100
  Window: 60s
  Burst: 10

Rates:
  1.67 requests/second
  100.00 requests/minute
  6000.00 requests/hour
  144000 requests/day

Intervals:
  Min interval between requests: 600.00ms

Token Bucket:
  Bucket size: 10
  Refill rate: 1.6667 tokens/second
  Refill interval: 600.00ms per token
  Time to refill bucket: 6.00s

Sliding Window:
  Window size: 60s
  Max in window: 100

Questions

Does Rate Limiter Calculator work offline?+

Yes. It is JavaScript running in this tab, so once the page has loaded it needs nothing further from the network. Put the machine in flight mode and it carries on. Nothing you do here is sent anywhere, because there is nowhere for it to go.

Does it remember anything between visits?+

No. Reload the page and it starts from nothing. There is no account, no saved state and no cookie holding your last session. That is a deliberate trade: it cannot lose your data because it never keeps any.

Is it accurate?+

Timing comes from performance.now(), the high resolution clock the browser provides, rather than from setInterval, which drifts by a few milliseconds every tick and compounds over minutes. What can still shift things is the browser throttling a tab in the background, so leave it visible if the timing matters.

Does it make a sound?+

Where a sound makes sense, it is generated with the Web Audio API rather than loaded as a file, so there is nothing to download and nothing to block. Browsers refuse to start audio until you have interacted with the page, which is why the first press is what switches it on.

Can I use Rate Limiter Calculator on a phone?+

Yes. The controls are sized for touch and the layout collapses to one column on a narrow screen. Bear in mind that a phone locking its screen will suspend the page, and timing stops with it.