Inworld AI review

Inworld AI was once best known for its NPC character engine, but its current product is a voice and inference platform, and its games page positions it as the voice layer for characters and narrated media. Realtime text to speech covers more than 200 languages with library voices, voice cloning from seconds of audio and voice design from a text prompt. Speech to text in 30+ languages returns signals such as emotion, pitch and vocal style, and speech to speech sessions handle turn detection and interruptions for live dialogue. An LLM router can send combat barks to fast open models and story scenes to stronger ones, with fallback across 100+ models. TTS streams word timestamps and visemes for lip sync. Everything is an API over REST, WebSocket or WebRTC that you call from Unreal, Unity or a custom engine. The Creator plan costs $25 a month and includes $25 in credits. The trade-off is that you build character logic yourself.

Who it is for

Developers who want low-cost, expressive character voices and live dialogue through an API.

Price

Pay-as-you-go option; Creator plan $25 per month with $25 in credits.

Creator Content creation and small projects $25 /mo
Quoted from the vendor pricing page on November 9, 2026.

Key features

• Realtime text to speech in 200+ languages with voice cloning and voice design
• Speech to text in 30+ languages with emotion, pitch and vocal style signals
• Speech to speech sessions with turn detection and barge-in
• LLM router across 100+ models with automatic fallback
• Word timestamps and visemes for realtime lip sync

Strengths and weaknesses

• Strength: Low TTS rates, from $20 per 1M characters on Creator
• Strength: Visemes in the audio stream help animated characters lip sync
• Strength: Credits roll over for 3 months
• Weakness: API only, with no visual NPC builder or engine plugin documented
• Weakness: No permanent free plan, only pay as you go
• Weakness: Character logic and memory are left to your own code

Key facts

• Creator plan: $25 per month, $25 in credits
• TTS languages: 200+
• STT languages: 30+
• Compliance: GDPR and SOC 2 Type II on every plan

Where it ranks

Inworld AI is No. 10 in our Best AI Tools for Game Developers verdict.