SiteIntel vs Userstack

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

Uptime · 30d
Uptime · 90d100%99.02%
Uptime · 30d100%98.3%
P50 · ms1005443
P95 · ms38493029
AuthapiKeyapiKey
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — key may be requiredFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

SiteIntel vs Userstack: common questions

Which is more reliable, SiteIntel or Userstack?

On our scheduled checks, SiteIntel leads on measured uptime — SiteIntel at 100% versus Userstack at 99.02% 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, SiteIntel or Userstack?

Userstack has the lower median latency in our checks — SiteIntel responds in 1005 ms versus Userstack at 443 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 SiteIntel and Userstack need an API key?

Both ask you to authenticate — SiteIntel uses an API key and Userstack 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 SiteIntel and Userstack from the browser?

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

Are SiteIntel and Userstack free for commercial use?

SiteIntel has unclear commercial terms, and Userstack 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.