Open Library vs Voidly

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

Uptime · 30d
Uptime · 90d86.0%86.0%
Uptime · 30d94.8%81.0%
P50 · ms11851865
P95 · ms49664655
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearyes
Data licenseMixed — mostly openCC BY 4.0
Free tierUnlimited within courtesy limitsFree (keyless data endpoints; Hydra ML endpoints need a key)
Rate limitSoft — identified UA appreciatedUnpublished
In directory since2026-05-022026-07-05
operationalpartialdownno data

Open Library vs Voidly: common questions

Which is more reliable, Open Library or Voidly?

Both are neck-and-neck — Open Library and Voidly each measure 86.0% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.

Which is faster, Open Library or Voidly?

Open Library has the lower median latency in our checks — Open Library responds in 1185 ms versus Voidly at 1865 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 Voidly need an API key?

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

Can I call Open Library and Voidly from the browser?

Yes — both Open Library and Voidly 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 Voidly free for commercial use?

Open Library has unclear commercial terms, and Voidly allows commercial use on its free tier. 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.