Compare AI tools

	Perplexity S	Windsurf A	NotebookLM S	Devin A
Tagline	AI search done right. Cited answers, not chat theater.	Codeium's agentic IDE. Cascade agent + strong free tier.	Google's research notebook. Turns your docs into a podcast.	Cognition Labs' autonomous coding engineer.
Category	Research	Coding	Research	Agents
Pricing	Free + $20/mo Pro	Free + $15/mo Pro	Free	$500/mo
Best for	Replacing Google for any question where you want a cited answer in seconds.	Developers who want Cursor-like power for less money.	Students, researchers, anyone with a stack of PDFs or a topic to learn.	Engineering teams offloading tickets. Ops/platform work.
Strengths	Sources every claim Fast, current answers Pro Search runs multi-step research Spaces for persistent context	Cheaper than Cursor Cascade agent for multi-file tasks Solid free tier	Upload anything, ask questions, get cited answers Audio Overview turns docs into a 10-min podcast Great for studying	Works like an engineer — takes Slack tasks, opens PRs Handles multi-hour engineering work Reports back with what it did
Weaknesses	Not a general chatbot Answers can be shallow on complex topics	Smaller community Model selection more limited	Google-only Can be slow on large corpora	Expensive Best for well-scoped tasks Not for solo hobbyists
Kai's verdict	S-tier for search. I use it before Google now. If you're still Googling everything, try this for a week.	A-tier. Close second to Cursor. If $5/mo matters, start here.	S-tier for study. The Audio Overview is a killer feature. Try it with three of your favorite PDFs.	A-tier for the right use case. Not for solo devs. If you manage engineers, try one license.
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