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