Compare AI tools

	Runway S	Hume AI A	Gemini A	NotebookLM S
Tagline	The pro's AI video tool. Gen-4 is the current bar.	Voice AI that reads + expresses emotion.	Google's answer. Best integrated with Workspace + free for a lot.	Google's research notebook. Turns your docs into a podcast.
Category	Video	Voice	Chatbots	Research
Pricing	Free + $15-$95/mo	Free tier + pay-as-you-go	Free + $20/mo Advanced (bundled with 2TB Drive)	Free
Best for	Marketing video, pitch decks, b-roll, creative shorts.	Therapy apps, customer service, any voice agent where emotion matters.	Anyone already on Google, research tasks, summarizing long documents.	Students, researchers, anyone with a stack of PDFs or a topic to learn.
Strengths	Most mature video workflow Character consistency via Act-One Gen-4 quality is production-grade	Detects + mirrors emotional tone EVI (Empathic Voice Interface) feels different Expressive voice output	Native Google Workspace integration Very long context (1M+) Deep Research feature Free tier is generous	Upload anything, ask questions, get cited answers Audio Overview turns docs into a 10-min podcast Great for studying
Weaknesses	Expensive at scale Still needs post-editing	Niche use case Pricing ramps fast	Writing quality trails Claude Over-refusals on edge content UI is cluttered	Google-only Can be slow on large corpora
Kai's verdict	S-tier. Market leader with reason. Start here for serious video.	A-tier in its niche. The only one that actually gets emotion right.	A-tier. The Deep Research feature is genuinely useful. Don't sleep on it if you're already paying Google.	S-tier for study. The Audio Overview is a killer feature. Try it with three of your favorite PDFs.
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