Inworld TTS-2 at $25 per 1M characters vs Sume TTS, one year of ads

Inworld's pricing page lists TTS-2 at $25 per 1M characters and TTS-2 Flash at $15 on the On-Demand plan (read 2026-10-09). Sume TTS comes to $47.50 per 1M characters, or $0.0475 per 1,000, because it reserves one provider credit per character at $38 per million credits x 1.25. For 144,000 characters a year, that is $3.60 on TTS-2, $2.16 on Flash and $6.84 on Sume.

What does the Inworld ladder look like?

What is the yearly bill for 20 ads a month?

Assume 20 ads a month at 600 characters each, 12 months: 144,000 characters.

Is the gap the whole story?

On characters alone, Inworld is cheaper. The difference on this workload is about $3 to $5 a year. Sume TTS is a job in the same API and wallet as video, captions and timeline renders, so the useful question is whether a separate voice vendor saves you more than it costs to wire. The Inworld paid plans also carry monthly credits ($25 to $1,500), which a low-volume team may not use.

When would I pick which?

• Voice-only product at high volume: compare the plan ladder, not the On-Demand rate.
• Video ads with a voice track: price the whole chain; a 600-character script is $0.0285 on Sume next to a clip that costs dollars.
• Always audition voices on both: price does not compare voices.

What is in Sume's TTS price?

Sume TTS 1.0 charges one provider credit per character, at $38 per million credits, times 1.25. The maximum request is 20,000 characters, so the most one request can cost is $0.95. It runs as an async job with status and result URLs and an optional signed webhook.

I have not compared voices, languages or latency, because the vendor page read today lists prices only. Use the character quote for budgeting and an audition for the decision.