Open Library vs Photon API

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

Uptime · 30d
Uptime · 90d88.2%99.02%
Uptime · 30d81.7%98.3%
P50 · ms1629710
P95 · ms48781598
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseMixed — mostly openUnverified
Free tierUnlimited within courtesy limitsFree — limits not published
Rate limitSoft — identified UA appreciatedUnpublished
In directory since2026-05-022026-07-05
operationalpartialdownno data

Open Library vs Photon API: common questions

Which is more reliable, Open Library or Photon API?

On our scheduled checks, Photon API leads on measured uptime — Open Library at 88.2% versus Photon API 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 Photon API?

Photon API has the lower median latency in our checks — Open Library responds in 1629 ms versus Photon API at 710 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 Photon API need an API key?

Neither needs a paid key — Open Library is callable with no signup, and Photon API is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call Open Library and Photon API from the browser?

Yes — both Open Library and Photon API 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 Open Library and Photon API free for commercial use?

Open Library has unclear commercial terms, and Photon API 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.