What is GPT Realtime 2?
GPT Realtime 2 is specifically designed for teams that require rapid speech synthesis, real-time subtitle feedback, and seamless transitions from prototype testing to API integration. It converts text into natural, fluent speech with a single click, making it ideal for scenarios such as help-center voice responses, course narration previews, podcast intros, and more. Users can input prompts directly without creating an account, choose from six stylized voice options—VoiceAlloy, Echo, Fable, Onyx, Nova, or Shimmer—and select WAV output format. Requests are initiated through the local /api/generate route, and via OpenRouter, users receive streamable audio along with synchronized subtitles.
Key features
It offers six preset voice styles: VoiceAlloy (neutral and balanced), Echo (warm and conversational), Fable (expressive), Onyx (deep and authoritative), Nova (friendly and upbeat), and Shimmer (clear and gentle). All voices are output in WAV format and ready to play immediately.
The developer-friendly API route (/api/generate) is ready to use out of the box, supporting configuration via the OPENROUTER_API_KEY environment variable (only applicable on server-side platforms like Vercel or .env.local). It also provides customizable features such as rate limiting, prompt templates, usage logging, fallback mechanisms, and error handling.
Use cases and audience
Developers who need fast voice generation, real-time text transcription feedback, and a smooth transition from web-based testing to API integration.
- Generate concise voice replies for help centers, chat workflows, and multilingual support queues.
- Create podcast intros, course narrations, and short-form voiceover drafts for pre-recording rehearsals
- Integrate with chat workflows that require streaming text transcription and audio output
Text prompts, along with options for voice style—such as Alloy, Echo, Fable, Onyx, Nova, or Shimmer—and output format (WAV).
Audio streams encoded in PCM16 are packaged into WAV format for playback, while a JSON response containing both the text transcription and audio data is returned.
Frequently asked questions
Do you need to register an account to try the web-based Playground?
No, you can try it instantly without registration.
Can GPT Realtime 2 be invoked within your own application?
Yes, you need to configure OPENROUTER_API_KEY in the server-side environment variables (such as Vercel or .env.local); do not place it in the browser-side code.
How to use
- 01
Input prompt
- 02
Select a voice style (such as Alloy, Echo, etc.) and an output format (WAV)
- 03
Send the request via the local /api/generate route
- 04
Receive and review the audio and text transcription in a streaming fashion through OpenRouter
Benefits and limitations
Benefits
- Browser testing requires no registration or login
- High-quality, human-like speech synthesis results
- Low-latency streaming response
- Easily integrated via the OpenRouter API
Limitations
- Generating actual audio outside of demo mode requires a private OpenRouter API key
- The cost of generating actual audio depends on the billing model of the OpenRouter provider
- Output formats are limited (primarily WAV provided via PCM16)
Pricing and availability
$0 Web experience: includes a demo of converting prompts into text transcription, voice and format control, no account required, and clear labeling of demo mode; for production environments, integration with OpenRouter is necessary, billing follows its openai/gpt-audio routing scheme, supporting streaming audio chunking and JSON output with text transcription.
- Pricing source
- https://gptrealtime2.ai/
- Pricing last updated
- 2026-10-30
Prices and limits may change. Check the official website for current terms.
Official website & sources
Updated on 2026-10-30
