OpenPLZ API vs US ZipCode
Same instrument, two spec sheets — measured, not claimed.
OpenPLZ API vs US ZipCode: common questions
Which is more reliable, OpenPLZ API or US ZipCode?
On our scheduled checks, US ZipCode leads on measured uptime — OpenPLZ API at —% versus US ZipCode 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 OpenPLZ API and US ZipCode need an API key?
OpenPLZ API needs no key, while US ZipCode requires a free API key. If you want to start calling without signup, reach for OpenPLZ API first.
Can I call OpenPLZ API and US ZipCode from the browser?
Yes — both OpenPLZ API and US ZipCode 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 OpenPLZ API and US ZipCode free for commercial use?
OpenPLZ API 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.