Cisco Spark vs PostStack

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

Uptime · 30d
Uptime · 90d100%100%
Uptime · 30d100%100%
P50 · ms16081066
P95 · ms29361890
AuthapiKeyapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — API key requiredFree tier — key may be required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Cisco Spark vs PostStack: common questions

Which is more reliable, Cisco Spark or PostStack?

Both are neck-and-neck — Cisco Spark and PostStack each measure 100% 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, Cisco Spark or PostStack?

PostStack has the lower median latency in our checks — Cisco Spark responds in 1608 ms versus PostStack at 1066 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 Cisco Spark and PostStack need an API key?

Both ask you to authenticate — Cisco Spark uses an API key and PostStack 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 Cisco Spark and PostStack from the browser?

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

Are Cisco Spark and PostStack free for commercial use?

Cisco Spark has unclear commercial terms, and PostStack 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.