City, Helsinki vs ONS

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

Uptime · 30d
Uptime · 90d52.9%100%
Uptime · 30d45.0%100%
P50 · ms710732
P95 · ms20521819
Authnonenone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree — limits not published
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

City, Helsinki vs ONS: common questions

Which is more reliable, City, Helsinki or ONS?

On our scheduled checks, ONS leads on measured uptime — City, Helsinki at 52.9% versus ONS at 100% 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, City, Helsinki or ONS?

City, Helsinki has the lower median latency in our checks — City, Helsinki responds in 710 ms versus ONS at 732 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 City, Helsinki and ONS need an API key?

Neither needs a paid key — City, Helsinki is callable with no signup, and ONS is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call City, Helsinki and ONS from the browser?

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

Are City, Helsinki and ONS free for commercial use?

City, Helsinki has unclear commercial terms, and ONS 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.