RainViewer vs Website Carbon
Same instrument, two spec sheets — measured, not claimed.
RainViewer vs Website Carbon: common questions
Which is more reliable, RainViewer or Website Carbon?
Both are neck-and-neck — RainViewer and Website Carbon each measure 100% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.
Which is faster, RainViewer or Website Carbon?
Website Carbon has the lower median latency in our checks — RainViewer responds in 551 ms versus Website Carbon at 37 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 RainViewer and Website Carbon need an API key?
Neither needs a paid key — RainViewer is callable with no signup, and Website Carbon is callable with no signup. Both are quick to prototype with; rate limits still apply.
Can I call RainViewer and Website Carbon from the browser?
Only RainViewer is browser-friendly — it returns CORS headers over HTTPS. Website Carbon needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are RainViewer and Website Carbon free for commercial use?
RainViewer has unclear commercial terms, and Website Carbon 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.