Image to Link vs Userstack

Same instrument, two spec sheets — measured, not claimed.

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
AuthnoneapiKey
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Image to Link vs Userstack: common questions

Which is more reliable, Image to Link or Userstack?

On our scheduled checks, Userstack leads on measured uptime — Image to Link 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 Image to Link and Userstack need an API key?

Image to Link needs no key, while Userstack requires a free API key. If you want to start calling without signup, reach for Image to Link first.

Can I call Image to Link and Userstack from the browser?

Yes — both Image to Link 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 Image to Link and Userstack free for commercial use?

Image to Link 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.