PaperClean vs Userstack
Same instrument, two spec sheets — measured, not claimed.
PaperClean vs Userstack: common questions
Which is more reliable, PaperClean or Userstack?
On our scheduled checks, Userstack leads on measured uptime — PaperClean 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 PaperClean and Userstack need an API key?
Both ask you to authenticate — PaperClean uses an API key and Userstack 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 PaperClean and Userstack from the browser?
Yes — both PaperClean 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 PaperClean and Userstack free for commercial use?
PaperClean 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.