Keyvalue vs serpstack

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

Uptime · 30d
Uptime · 90d86.3%99.02%
Uptime · 30d80.0%98.3%
P50 · ms855492
P95 · ms20511442
AuthnoneapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — key may be required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Keyvalue vs serpstack: common questions

Which is more reliable, Keyvalue or serpstack?

On our scheduled checks, serpstack leads on measured uptime — Keyvalue at 86.3% versus serpstack 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, Keyvalue or serpstack?

serpstack has the lower median latency in our checks — Keyvalue responds in 855 ms versus serpstack at 492 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 Keyvalue and serpstack need an API key?

Keyvalue needs no key, while serpstack requires a free API key. If you want to start calling without signup, reach for Keyvalue first.

Can I call Keyvalue and serpstack from the browser?

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

Are Keyvalue and serpstack free for commercial use?

Keyvalue has unclear commercial terms, and serpstack 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.