Userstack vs YADG

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

Uptime · 30d
Uptime · 90d99.02%2.9%
Uptime · 30d98.3%0.0%
P50 · ms4431308
P95 · ms30291359
AuthapiKeyapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — API key requiredFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Userstack vs YADG: common questions

Which is more reliable, Userstack or YADG?

On our scheduled checks, Userstack leads on measured uptime — Userstack at 99.02% versus YADG at 2.9% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Which is faster, Userstack or YADG?

Userstack has the lower median latency in our checks — Userstack responds in 443 ms versus YADG at 1308 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 YADG need an API key?

Both ask you to authenticate — Userstack uses an API key and YADG uses an API key. Each key is free to obtain; the Auth and Card-required rows above spell out the signup terms.

Can I call Userstack and YADG from the browser?

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

Are Userstack and YADG free for commercial use?

Userstack has unclear commercial terms, and YADG 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.