IsItWater vs US ZipCode
Same instrument, two spec sheets — measured, not claimed.
IsItWater vs US ZipCode: common questions
Which is more reliable, IsItWater or US ZipCode?
Both are neck-and-neck — IsItWater and US ZipCode each measure 0.0% 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.
Do IsItWater and US ZipCode need an API key?
Both ask you to authenticate — IsItWater uses an API key and US ZipCode uses an API key. Each key is free to obtain; the Auth and Card-required rows above spell out the signup terms.
Can I call IsItWater and US ZipCode from the browser?
Only US ZipCode is browser-friendly — it returns CORS headers over HTTPS. IsItWater needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are IsItWater and US ZipCode free for commercial use?
IsItWater has unclear commercial terms, and US ZipCode 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.