Keyvalue vs serpstack

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
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 —% versus serpstack at —% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

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.