Gemini TTS: Gemini 3.8 Flash Text to Speech

Recorded on 2026-10-02. Four direct requests in this tool's request format (voices Kore, Charon and Puck, one in Chinese), each with a delivery note: scripts of 36 to 120 characters returned 6.2 to 12.1 seconds of 24 kHz mono WAV, 7 to 9 seconds after each request. A listener model that was not shown the scripts transcribed all four word for word, heard the laugh written as <laugh>, and described the "slow, low and a little mysterious" reading as slow and ominous. Four voice-overs made by clicking through this page on a local build were each charged once (2 credits), could be played 12 to 30 seconds after the click (12, 12, 21 and 30), downloaded as WAV for their owner and returned 401 to a signed-out request. A refused, failed, unusable or overdue provider result returned the credits. In a separate check all 30 voices returned audio, and a made-up voice name was refused. Flash Lite (same day): two direct requests with the same scripts and voices returned 8.2 and 13.2 seconds of the same 24 kHz WAV, 16 and 10 seconds after each request, at 1 credit each; the listener transcribed both word for word and described the second as whispered and mysterious. Four Flash Lite voice-overs made by clicking through this page were charged 1 credit each and could be played 12 to 21 seconds after the click. An earlier one took 123 seconds; since then each request goes to the provider's queue once and is checked on every second, so a slow one does not hold up other jobs. Prices follow fal's list prices (USD 0.045 per 1,000 characters on Flash, 0.03 on Flash Lite) at 250 credits per USD. Long scripts (direct requests, same day): 3,000 English characters took 44 to 70 seconds on Flash and 87 to 211 on Flash Lite (3 to 4 minutes of speech). An original Chinese story was read in versions of 491, 669, 847 and 1,018 characters, and a listener transcribed 25-second samples from the start, the middle and the end of every recording: up to 847 characters both models read to the end in all ten runs (Flash three, Flash Lite seven); at 1,018 characters Flash did so in three runs of three, and Flash Lite dropped the last paragraph in two runs of four, one of them made through this page (8 credits, ready after 187 seconds). Scripts with a repeating pattern went wrong: a numbered list of 1,500 Chinese characters made Flash Lite read on past the last item with items of its own and made Flash repeat one; 2,876 characters of the same list ran Flash Lite up to an invented item 200 and failed on Flash at the provider's five-minute limit. A 2,900-character Chinese script sent through this page on Flash Lite failed the same way and its credits were returned. One request is therefore limited to 3,000 characters with Chinese, Japanese and Korean characters counted as four (750 per request). Multi-speaker dialogue and longer scripts are not offered here.

• Gemini 3.8 Flash TTS on fal — API specification
• Gemini 3.8 Flash Lite TTS on fal — API specification

Updated Oct 2, 2026 · How we test