Chronicling America vs IPASIS

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

Uptime · 30d
Uptime · 90d0.0%0.0%
Uptime · 30d0.0%0.0%
P50 · ms
P95 · ms
AuthnoneapiKey
CORSnono
HTTPSyesyes
Card requirednono
Commercial useyesunclear
Data licensePublic domain / no known copyright (Library of Congress)Unverified
Free tierFree — public-domain collection dataFree tier — API key required
Rate limitLoC throttles heavy crawling (see LoC API policy)Unpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Chronicling America vs IPASIS: common questions

Which is more reliable, Chronicling America or IPASIS?

Both are neck-and-neck — Chronicling America and IPASIS each measure 0.0% 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.

Do Chronicling America and IPASIS need an API key?

Chronicling America needs no key, while IPASIS requires a free API key. If you want to start calling without signup, reach for Chronicling America first.

Can I call Chronicling America and IPASIS from the browser?

Neither sends browser-friendly CORS headers reliably, so call Chronicling America and IPASIS from a server or proxy rather than client-side. The CORS and HTTPS rows above show exactly what we detected for each.

Are Chronicling America and IPASIS free for commercial use?

Chronicling America allows commercial use on its free tier, and IPASIS 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.