ByteDance · AI audio
Seed Audio 1.0
Generate expressive speech and audio from a detailed text prompt with direct speed, volume, pitch, and sample-rate controls.
- expressive speech
- audio direction
- prompt-based audio
30 credits per generation.
Text to speech and voice design
AI Voice Generator
Turn a script into expressive audio with three current models for prompt-guided sound, custom voice design, and production-ready speech.
- 35 free monthly credits
- No provider API keys
- Credit price shown by model
Your generated audio will appear here.
Enter a prompt and click 'Generate' to start.
Model guide
Choose the right AI voice model
Start with the kind of control you need, then compare language support, reference inputs, voice settings, and credit cost.
| Model | Approach | Best for | Credit cost |
|---|---|---|---|
| Seed Audio 1.0 ByteDance | Prompt-guided audio | expressive speech, audio direction, prompt-based audio | 30 credits per generation. |
| Qwen 3 TTS Voice Design Alibaba | Designed voice | custom voice design, multilingual speech, character voices | From 1 credit per 100 characters. |
| Eleven V3 ElevenLabs | Preset voices | natural narration, expressive voiceover, preset voices | 10 credits per 1,000 characters. |
Alibaba · AI audio
Qwen 3 TTS Voice Design
Describe a custom voice in natural language, then synthesize speech in ten supported languages.
- custom voice design
- multilingual speech
- character voices
From 1 credit per 100 characters.
ElevenLabs · AI audio
Eleven V3
Generate expressive speech with preset voices and direct control over stability, similarity, and speaker boost.
- natural narration
- expressive voiceover
- preset voices
10 credits per 1,000 characters.
Examples
Hear each AI voice model
Compare prompt-guided atmosphere, a voice built from a description, and polished narration from a preset voice. Press play — the waveform is drawn from the actual audio, and you can click it to scrub.
Seed Audio 1.0
Last-minute goal call
A last-minute goal call that builds from controlled commentary to a full shout, with stadium atmosphere.
0:00
- Settings
- MP3 · 44.1 kHz · Speed 1 · Volume 1 · Pitch 0
- Listen for
- The escalation inside one take, crowd bed reacting to the goal, and intelligibility at the shout.
View prompt
Prompt
A packed football stadium at night, 60,000 fans roaring, rain drumming on the stands, a commentator leaning into his microphone in the broadcast booth, his voice rising with the attack. He calls the final minute of the match: "Here comes Mercer, past one defender... past TWO! He's got space on the edge of the box — Mercer SHOOTS— GOAL! GOAL! Unbelievable! In the ninety-first minute! The rookie has done it — the stadium is on its feet!" Excited sports commentator voice, breathless and electric, starting controlled and building to a full-throated shout, crowd noise surging underneath, no music.
Qwen 3 TTS Voice Design
The lighthouse keeper
An elderly lighthouse keeper voice designed entirely from a natural-language description.
0:00
- Settings
- Language · English
- Listen for
- The gravel texture, coastal lilt, pauses on the ellipses, and warmth underneath the age.
View prompt
Voice description
An elderly lighthouse keeper, male, in his seventies. A gravelly, weathered voice with a gentle coastal English lilt, slow and deliberate pacing, thoughtful pauses between phrases, warm underneath the roughness — the sound of a man who has told this story a hundred times and still finds it wondrous. Intimate, fireside storytelling delivery.
Text
Forty years I kept that light... and I still remember the night the storm took the Eleanor. The sea was black as ink — and then, out of nowhere, this tiny green flare, bobbing in the waves. A survivor. One small light... answering mine. That's the thing about lighthouses, lad. They don't save ships. They just remind people... where the land is.
Eleven V3
Details set the day in motion
A documentary-style brand narration with controlled dynamics from the Sarah preset voice.
0:00
- Settings
- Sarah · Stability 0.4 · Similarity 1 · Speaker boost on
- Listen for
- The short-sentence rhythm, lift before “RenderFlow AI,” and settle on the final line.
View prompt
Prompt
Every morning, before the city wakes, thousands of small decisions set the day in motion. The roaster who checks the beans one more time. The driver who leaves ten minutes early, just in case. The nurse who rereads the chart at the door. RenderFlow AI was built for people like that — people who care about the details. Because when the details are right... everything else follows.
Use cases
Create audio for real production work
Use a preset when speed matters, design a voice when identity matters, or write detailed direction when the sound needs more control.
Narration and explainers
Turn scripts into clear voiceover for product tours, courses, presentations, and documentary-style content.
Character voice design
Describe age, accent, tone, emotion, and delivery to create a distinctive voice for stories, games, and creative projects.
Marketing and social audio
Produce short ads, campaign reads, podcast intros, and social voiceovers without coordinating a recording session.
Multilingual speech
Generate speech across supported languages while keeping voice direction and delivery consistent between versions.
Workflow
From script to finished voiceover
Good voice direction separates what is said from how it should sound.
-
01
Choose a voice model
Select prompt-guided audio, natural-language voice design, or a preset production voice.
-
02
Write the script
Enter the exact words to speak and keep sentences punctuated for the pauses and rhythm you want.
-
03
Direct the delivery
Set a voice description, preset, speed, pitch, stability, or reference input when the selected model supports it.
-
04
Generate and review
Listen for pronunciation, pace, and emotion, then refine one direction at a time before generating again.
Voice direction formula
[Speaker identity] with [accent and vocal texture], speaking at [pace] with [emotion and energy] for [audience or context].
Practical details
Frequently asked questions
Which AI voice model should I use?
Seed Audio 1.0 is a strong fit for expressive speech and audio direction. Qwen 3 TTS Voice Design is a strong fit for custom voice design and multilingual speech. Eleven V3 is a strong fit for natural narration and expressive voiceover.
What is voice design?
Voice design creates a voice from a written description rather than making you choose only from a fixed preset list. Describe traits such as age, accent, texture, emotion, pace, and delivery style.
What format does Seed Audio generate?
Seed Audio 1.0 generates MP3 audio in RenderFlow AI.
Which languages are supported?
Qwen 3 TTS Voice Design supports automatic language detection plus Chinese, English, German, Italian, Portuguese, Spanish, Japanese, Korean, French, and Russian. Language support varies by model.
How should I write a voice description?
Start with the speaker, then specify accent, pitch, texture, pace, emotion, and context. For example: a warm middle-aged narrator with a clear British accent, measured pace, and restrained confidence.
Can I try the AI voice generator for free?
Yes. New RenderFlow AI accounts receive 35 monthly credits on the Free plan, with no credit card required.
How many credits does voice generation cost?
Seed Audio 1.0: 30 credits per generation. Qwen 3 TTS Voice Design: From 1 credit per 100 characters. Eleven V3: 10 credits per 1,000 characters.
Do I need provider API keys?
No. RenderFlow AI handles provider access, so you can use the available voice models through one account and credit balance.