TTS Without API Key: Free Browser-Based Text to Speech
If you’ve ever tried to use text-to-speech and hit a paywall or API key requirement, you know the frustration. Most TTS tools require signing up, getting an API key, and paying per character.
But there’s a better way: browser-based TTS that runs entirely on your device. Our TTS tool proves it — 88 voices, 9 languages, zero API keys.
The Problem with API-Based TTS
Traditional TTS services follow a pattern:
- Sign up for an account
- Get an API key
- Pay per character (typically $0.0001 to $0.03 per character)
- Send your text to their server
- Receive audio back
This works, but it has problems:
Privacy: Your text is sent to a remote server. For confidential documents, legal text, or personal content, this is a dealbreaker.
Cost: At scale, per-character pricing adds up. A 10,000-word document costs $1-30 depending on the service.
Dependency: If the API goes down, your tool stops working. If they change pricing, your costs change.
Limits: Free tiers are throttled. Rate limits cap how fast you can generate.
How No-API TTS Works
Browser-based TTS uses WebAssembly or WebGPU to run AI models directly in your browser:
- You open the website
- The AI model downloads to your browser (one-time, ~90MB with Small model)
- Model is cached in IndexedDB
- All future text-to-speech happens locally
- Text never leaves your device
No API key. No account. No server. No cost.
OfflineTTS: TTS Without API
OfflineTTS is a browser-based text-to-speech tool that runs the Kokoro TTS model (82M parameters) locally:
- 54 voices across 9 languages (American English, British English, Japanese, Mandarin Chinese, Spanish, French, Hindi, Italian, Brazilian Portuguese)
- Works offline after initial model download
- No signup or API key — just open and use
- Free — it runs on your hardware, not ours
- Private — your text never leaves your browser
Technical Details
The Kokoro TTS model is converted to ONNX format and runs via ONNX Runtime Web:
- WebGPU provides GPU acceleration (Chrome 113+, Safari 17.4+, Edge 113+)
- WebAssembly provides CPU fallback (all modern browsers)
- Model files are cached in IndexedDB after first download
- Audio output uses the Web Audio API for playback
- WAV export for downloading generated audio
Comparison: API TTS vs. No-API TTS
| Feature | API TTS (ElevenLabs, etc.) | No-API TTS (OfflineTTS) |
|---|---|---|
| API Key Required | ✅ | ❌ |
| Signup Required | ✅ | ❌ |
| Per-Character Cost | ✅ | ❌ |
| Works Offline | ❌ | ✅ |
| Privacy | Server processes text | Text stays on device |
| Speed | Depends on API latency | Depends on device hardware |
| Quality | High | High |
| Rate Limits | ✅ | ❌ |
When to Use Each
Use API TTS when:
- You need the absolute highest quality voices (ElevenLabs)
- You’re processing millions of characters per day
- You need server-side processing
Use No-API TTS when:
- You value privacy
- You want zero cost at any usage level
- You need offline capability
- You’re a content creator doing daily voice-overs
- You’re a developer building privacy-first apps
Getting Started
It takes 30 seconds:
- Go to offlinetts.com/app
- Click “Load Model” (one-time download, ~90MB for Small model)
- Type your text
- Choose a voice
- Generate speech
No account. No API key. No cost.