Wit.ai

Wit.ai is Meta's free natural-language platform for turning text or speech into structured intent — the toolkit for teaching your app to understand "book me a table for four at eight" as a reservation request with specific parameters.

You train it by example: provide sample phrases, label the intents and entities inside them, and Wit learns to parse new variations. It handles many languages, supports speech input alongside text, and exposes everything through a simple API with SDKs. Its most remarkable feature remains the price: free, with no usage tier gymnastics — unusual in a category where NLU platforms charge per request.

Strengths: free for production use, genuinely easy to start (a working intent model in an afternoon), decent multilingual support, and Meta's infrastructure behind it. Weaknesses: development pace has been quiet compared to LLM-based alternatives; modern language models often handle intent extraction more flexibly without training data; support is community-driven; and your training data lives with Meta — a consideration for sensitive domains.

Who it's for: developers and students building chatbots, voice commands or command parsers on a zero budget — and anyone wanting to learn NLU fundamentals with a forgiving, free platform.