TTS 1 Hd
High-definition text-to-speech model from OpenAI prioritizing audio clarity, natural prosody, and fidelity for broadcast and narration use cases.
OpenAI
OpenAI
Specifications
Context window, ranked against other audio speech models
Insufficient data
No published context window for this model or its peers.
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audio speech
Pricing
Rates are read live
Pricing for tts-1-hd is fetched from the live catalogue on load, so it is never served from a cache that could outlive a repricing.
Availability
Not enough data yet
We have not collected enough health probes for this model to publish an uptime or latency figure. A percentage from a handful of samples is fabricated precision, so none is shown until the sample count supports one.
How TTS 1 Hd is billed
Billed at the provider's list price, with no per-token markup.
- Exact list price
- Tokens settle at the published rate of the model that served your call.
- Cache discounts passed through
- Provider prompt-caching discounts reach your balance with no added fee.
- Cost on every response
- Each response carries the
x-nr-request-costheader, so you can reconcile spend per request.
More from OpenAI
Frequently asked questions
What is TTS 1 Hd?
High-definition text-to-speech model from OpenAI prioritizing audio clarity, natural prosody, and fidelity for broadcast and narration use cases.
How much does TTS 1 Hd cost?
TTS 1 Hd is billed at the provider's list price on nRouter with no per-token markup — tokens settle at the exact upstream rate. Input and output rates are read live, so see the pricing section above for the current figures.
Does TTS 1 Hd support tool calling and structured outputs?
No. TTS 1 Hd does not support tool calling, so it cannot invoke external tools or functions.
What inputs and outputs does TTS 1 Hd support?
TTS 1 Hd is a audio speech model. See the specifications section above for its exact supported input and output modalities.
How do I use TTS 1 Hd via nRouter?
Use any OpenAI-compatible client: point it at https://api.nrouter.ai/v1 with your nRouter API key and set the model to "openai/tts-1-hd".
When was TTS 1 Hd released?
TTS 1 Hd was released on November 6, 2023.
Where is the TTS 1 Hd documentation?
Start at nrouter.ai/docs. The quick-start guide (nrouter.ai/docs/getting-started/quick-start) covers API keys and your first request, and the API reference (nrouter.ai/docs/api-reference) lists every parameter.
What other audio models does OpenAI have?
Other OpenAI audio models on nRouter include Whisper 1 (nrouter.ai/models/whisper-1), o1 (nrouter.ai/models/o1), GPT-5.5 Pro (nrouter.ai/models/gpt-5.5-pro), GPT-4o Mini TTS (nrouter.ai/models/gpt-4o-mini-tts-2025-12-15).
Pricing is live — see above for current rates.