Gemini 3.8 Flash TTS price: audio-time vs per-character

Gemini 3.8 Flash TTS Standard is priced at $0.00225 per 10 seconds of audio output through Dec 31, 2026, and $0.0045 per 10 seconds from Jan 1, 2027, per Google's pricing page. That is a price on audio time. Sume's TTS is priced on characters of text, so the two only compare once you fix how many seconds a script speaks.

Google's changelog lists Gemini 3.8 Flash TTS and Flash-Lite TTS as generally available on Sep 22, 2026. Both pages were read 2026-09-30.

What does Gemini 3.8 Flash TTS cost per minute of audio?

The pricing page gives text input and audio output rates, and a per-10-seconds figure for the audio. Multiplying that figure by six gives a per-minute number. The rates below are Standard tier; Google says Batch and Flex rise similarly and Priority doubles.

How does Sume price the same voiceover?

Sume's text-to-speech row is $0.0475 per 1,000 characters. The code comment on the underlying table says standard Sonic TTS is about one Cartesia credit per transcript character, and the request schema counts spaces and punctuation toward usage with a maximum of 20,000 characters per job. The TTS Router catalog is described as "Sonic only" with pricing at the TTS 1.0 list times a 1.10 character book. Gemini voices are not in that list.

Read the current number on the API pricing page; the billing docs point there for what a generation costs.

How do I turn audio seconds into a character budget?

You need one number of your own: how many seconds your voice reads a character. Measure it by generating a few representative scripts, then divide audio seconds by character count. Neither vendor page states a seconds-per-character figure, so this post does not assume one.

With that measured rate, the Gemini cost for a script is its seconds divided by 10, times the per-10-second price. The Sume cost is its character count divided by 1,000, times the per-1,000-character price. Keep both in the same spreadsheet and re-run the Gemini column after Jan 1, 2027.

Does the January 2027 change affect a Sume budget?

No. The Gemini change applies to Google's price for its own model. A Sume voiceover budget moves only when the Sume rate card moves. If you want a second voice option next to Gemini, the Eleven v4 TTS jobs post shows how Sume's router handles async speech, and AI voiceover for ads covers the workflow.