The SMS Works API vs TimeZones iCal Library

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
AuthapiKeynone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — API key requiredFree — limits not published
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

The SMS Works API vs TimeZones iCal Library: common questions

Which is more reliable, The SMS Works API or TimeZones iCal Library?

On our scheduled checks, TimeZones iCal Library leads on measured uptime — The SMS Works API at —% versus TimeZones iCal Library 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 The SMS Works API and TimeZones iCal Library need an API key?

TimeZones iCal Library needs no key, while The SMS Works API requires a free API key. If you want to start calling without signup, reach for TimeZones iCal Library first.

Can I call The SMS Works API and TimeZones iCal Library from the browser?

Yes — both The SMS Works API and TimeZones iCal Library send CORS headers over HTTPS, so front-end code can fetch either directly with no backend proxy. That makes them easy to swap in a client-side app while you compare responses.

Are The SMS Works API and TimeZones iCal Library free for commercial use?

The SMS Works API has unclear commercial terms, and TimeZones iCal Library 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.