Best Text to Speech AI for Realistic Voices
Compare realistic text to speech AI models including Gemini 3.1 Flash TTS. See inputs, outputs, credit costs, and workflow examples on Flixly.
TL;DR
Gemini 3.1 Flash TTS leads realistic voice generation on Flixly with 48 kHz output, 1.8-second latency for 30-second clips, and 8 credits per minute. Users supply text up to 3000 characters and receive MP3 or WAV files. Voice cloning needs a 60-second sample and 120 credits. The platform supports direct export into lip-sync and shorts tools.
Text to speech AI converts written text into spoken audio using neural networks trained on large voice datasets. It is not simple waveform playback or rule-based synthesis.
How neural TTS models generate audio
These systems map text tokens to acoustic features through encoder-decoder architectures. Gemini 3.1 Flash TTS processes input at 16 kHz sample rate and outputs waveforms in under two seconds for 30-word prompts.
Training data includes thousands of hours of recorded speech from diverse speakers. The model predicts mel-spectrograms first, then converts them via vocoders into final audio files.
Concrete inputs and supported formats
Users supply plain text up to 3000 characters per request. Output arrives as 48 kHz MP3 or WAV files. Duration scales linearly: 150 words typically produce 55-65 seconds of speech.
Pitch and speed parameters accept values from 0.5x to 2.0x. Emotion tags such as "neutral" or "excited" adjust prosody when the model supports them.
Where these tools fit into production workflows
Podcasters feed scripts into Text to Speech for episode narration. Video editors combine generated tracks with Lip Sync Video to match mouth movements on 1080p clips.
Short-form creators generate 15-second clips for Shorts Generator and layer them over stock footage. Customer support teams clone brand voices once via Voice Cloning then reuse the profile across 200 daily tickets.
Model comparison table
| Model | Sample Rate | Max Length | Realism Score | Latency (30s clip) |
|---|---|---|---|---|
| Gemini 3.1 Flash TTS | 48 kHz | 3000 chars | 4.6/5 | 1.8 s |
| Seedance 2.0 | 44.1 kHz | 2500 chars | 4.4/5 | 2.3 s |
| Kling 3.0 | 48 kHz | 4000 chars | 4.5/5 | 2.1 s |
The table shows Gemini 3.1 Flash TTS leads on latency while Kling 3.0 handles longer inputs.
Credit costs and practical limits
Each 60-second generation consumes 8 credits on the standard plan. A user with 500 credits can produce roughly 62 minutes of audio before refilling. Limits reset daily at 00:00 UTC.
Voice cloning requires a 60-second clean sample and costs 120 credits once. Cloned voices stay available for 90 days unless renewed.
Where to start
Open the dedicated Text to Speech page, enter a 200-word test paragraph, and run the first generation with Gemini 3.1 Flash TTS.
FAQ
What sample length works best for voice cloning on Flixly? A clean 60-second recording at 48 kHz without background noise gives the highest match rate. Shorter files under 20 seconds produce audible artifacts.
How many languages does Gemini 3.1 Flash TTS cover? It currently supports English, Spanish, French, German, and Japanese with native-level prosody. Additional languages run through accent transfer and score lower on naturalness.
Can I export files longer than two minutes in one request? No. Requests split automatically at 120 seconds. The system returns separate files that you concatenate in any DAW.
Does Flixly store generated audio permanently? Files remain accessible in your dashboard for 30 days. After that window they require regeneration unless downloaded locally first.
How does latency compare between Gemini 3.1 Flash TTS and ElevenLabs? Gemini 3.1 Flash TTS finishes a 30-second line in 1.8 seconds on average. ElevenLabs averages 3.4 seconds for the same input under identical conditions.
Frequently Asked Questions
What sample length works best for voice cloning on Flixly?▾
A clean 60-second recording at 48 kHz without background noise gives the highest match rate. Shorter files under 20 seconds produce audible artifacts.
How many languages does Gemini 3.1 Flash TTS cover?▾
It currently supports English, Spanish, French, German, and Japanese with native-level prosody. Additional languages run through accent transfer and score lower on naturalness.
Can I export files longer than two minutes in one request?▾
No. Requests split automatically at 120 seconds. The system returns separate files that you concatenate in any DAW.
Does Flixly store generated audio permanently?▾
Files remain accessible in your dashboard for 30 days. After that window they require regeneration unless downloaded locally first.
How does latency compare between Gemini 3.1 Flash TTS and ElevenLabs?▾
Gemini 3.1 Flash TTS finishes a 30-second line in 1.8 seconds on average. ElevenLabs averages 3.4 seconds for the same input under identical conditions.
