Userstack vs What The Commit

Same instrument, two spec sheets — measured, not claimed.

Uptime · 30d
Uptime · 90d99.02%99.02%
Uptime · 30d98.3%98.3%
P50 · ms4431312
P95 · ms30294279
AuthapiKeynone
CORSyesyes
HTTPSyesno
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — API key requiredFree — limits not published
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Userstack vs What The Commit: common questions

Which is more reliable, Userstack or What The Commit?

Both are neck-and-neck — Userstack and What The Commit each measure 99.02% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.

Which is faster, Userstack or What The Commit?

Userstack has the lower median latency in our checks — Userstack responds in 443 ms versus What The Commit at 1312 ms (P50). Tail latency (P95) is in the table above; for most workloads the median is the number that shapes how the API feels.

Do Userstack and What The Commit need an API key?

What The Commit needs no key, while Userstack requires a free API key. If you want to start calling without signup, reach for What The Commit first.

Can I call Userstack and What The Commit from the browser?

Only Userstack is browser-friendly — it returns CORS headers over HTTPS. What The Commit needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are Userstack and What The Commit free for commercial use?

Userstack has unclear commercial terms, and What The Commit has unclear commercial terms. We track service terms and the data license as separate fields — see the Commercial use and Data license rows above, and confirm both before shipping either in a paid product.