Inworld TTS review

Inworld sells two realtime text-to-speech models. Realtime TTS-2 Flash is built for latency, with first audio as low as 50 ms, and costs $15 per million characters on the On-Demand plan. Realtime TTS-2 is the expressive model, taking delivery directions in plain words either for the whole request or in brackets mid-line, at $25 per million characters. Inworld says one TTS-2 voice speaks about 500 languages and dialects, and both models render 50 non-verbal sounds. Both stream over WebSocket and HTTP, and an OpenAI-compatible endpoint lets you point the OpenAI SDK at Inworld with few code changes. Monthly plans from $25 to $1,500 buy credits and cut rates, down to $7 per million characters for TTS-2 Flash on Growth. Cloned and designed voices cost the same as stock voices. Compliance add-ons such as HIPAA sit on the top self-serve tier, and no on-prem option is listed.

Who it is for

Consumer apps and agents that want low latency and many languages at a low per-character rate.

Price

On-Demand pay as you go at $15 per million characters for TTS-2 Flash and $25 for TTS-2; Creator plan $25 per month with lower rates.

TTS-2 Flash $15/1M chars
Quoted from the vendor pricing page on November 7, 2026.

Key features

• Realtime TTS-2 Flash with first audio as low as 50 ms
• Realtime TTS-2 voices that speak about 500 languages and dialects
• Delivery steering in plain words, inline or for a whole request
• Instant and professional voice cloning at the same price as stock voices
• OpenAI-compatible endpoint and up to 100,000 characters per long-form request

Strengths and weaknesses

• Strength: Lowest per-character rate among the agent-focused vendors here
• Strength: Lowest published time to first audio in this list
• Strength: OpenAI SDK compatibility makes switching quick
• Weakness: Deeper discounts require monthly plans from $25 to $1,500
• Weakness: HIPAA and BAA are add-ons on the $1,500 Growth plan
• Weakness: No on-prem deployment listed

Key facts

• Latency: As low as 50 ms to first audio (TTS-2 Flash)
• Languages: About 500 languages and dialects (TTS-2)
• Compliance: GDPR and SOC 2 Type II on every plan

Where it ranks

Inworld TTS is No. 4 in our Best Text-to-Speech APIs verdict.