Free Dictionary vs Gutendex

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseContent under source licenses (CC BY-SA 4.0 seen on entries)Public domain (Project Gutenberg data)
Free tierFree — limits not publishedFree, no key
Rate limit450 req/window · 417 remaining · resets 1783512354Unpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Free Dictionary vs Gutendex: common questions

Which is more reliable, Free Dictionary or Gutendex?

On our scheduled checks, Gutendex leads on measured uptime — Free Dictionary at —% versus Gutendex 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 Free Dictionary and Gutendex need an API key?

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

Can I call Free Dictionary and Gutendex from the browser?

Yes — both Free Dictionary and Gutendex 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 Free Dictionary and Gutendex free for commercial use?

Free Dictionary has unclear commercial terms, and Gutendex 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.