RSQ API vs serpstack

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

Uptime · 30d
Uptime · 90d100%99.02%
Uptime · 30d100%98.3%
P50 · ms783492
P95 · ms13871442
AuthnoneapiKey
CORSyesno
HTTPSnoyes
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

RSQ API vs serpstack: common questions

Which is more reliable, RSQ API or serpstack?

On our scheduled checks, RSQ API leads on measured uptime — RSQ API at 100% 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, RSQ API or serpstack?

serpstack has the lower median latency in our checks — RSQ API responds in 783 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 RSQ API and serpstack need an API key?

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

Can I call RSQ API and serpstack from the browser?

Neither sends browser-friendly CORS headers reliably, so call RSQ API and serpstack from a server or proxy rather than client-side. The CORS and HTTPS rows above show exactly what we detected for each.

Are RSQ API and serpstack free for commercial use?

RSQ API 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.