Compare software

Asta vs SciSpace: catalog facts
Asta	SciSpace
Free Offered by Ai2 as a research project; no paid plans are listed.	Freemium Free sign-up, with paid plans for more usage and enterprise options.
Web	Web
Large corpus of 108M+ abstracts and 12M+ full-text papers Built by Ai2, the institute behind Semantic Scholar	Search across more than 280 million papers Chat with PDF to explain difficult papers
Web only Little detail about features is available on the homepage	AI summaries of papers still need checking against the source Full features require a paid plan
Web application	Web application
Closed source	Closed source
License not stated	License not stated
Not stated if an account is needed	Account needed
Needs internet	Needs internet
Official website Full listing and sources Checked September 26, 2026	Official website Full listing and sources Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.