Open Library vs Web of Science API Expanded

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

Uptime · 30d
Uptime · 90d88.2%99.02%
Uptime · 30d81.7%98.3%
P50 · ms1629787
P95 · ms48781985
AuthnoneapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseMixed — mostly openUnverified
Free tierUnlimited within courtesy limitsFree tier — API key required
Rate limitSoft — identified UA appreciatedUnpublished
In directory since2026-05-022026-07-05
operationalpartialdownno data

Open Library vs Web of Science API Expanded: common questions

Which is more reliable, Open Library or Web of Science API Expanded?

On our scheduled checks, Web of Science API Expanded leads on measured uptime — Open Library at 88.2% versus Web of Science API Expanded at 99.02% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Which is faster, Open Library or Web of Science API Expanded?

Web of Science API Expanded has the lower median latency in our checks — Open Library responds in 1629 ms versus Web of Science API Expanded at 787 ms (P50). Tail latency (P95) is in the table above; for most workloads the median is the number that shapes how the API feels.

Do Open Library and Web of Science API Expanded need an API key?

Open Library needs no key, while Web of Science API Expanded requires a free API key. If you want to start calling without signup, reach for Open Library first.

Can I call Open Library and Web of Science API Expanded from the browser?

Only Open Library is browser-friendly — it returns CORS headers over HTTPS. Web of Science API Expanded needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are Open Library and Web of Science API Expanded free for commercial use?

Open Library has unclear commercial terms, and Web of Science API Expanded 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.