GPT-4o Mini TTS
Audio speech model by OpenAI.
OpenAI text-to-speech voice generation model. Converts input text into natural, expressive spoken audio across multiple voice styles.
This model is deprecated
GPT-4o Mini TTS has been deprecated. It is still served on nRouter and can still be called.
Caller Notice: To help identify integrations still relying on this model, all API responses now include x-nr-model-deprecated: true and Warning: 299 - "Model deprecated" headers.
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 gpt-4o-mini-tts-2025-12-15 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 GPT-4o Mini TTS 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
FAQs
What is GPT-4o Mini TTS?
OpenAI text-to-speech voice generation model. Converts input text into natural, expressive spoken audio across multiple voice styles.
How much does GPT-4o Mini TTS cost?
GPT-4o Mini TTS 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 GPT-4o Mini TTS support tool calling and structured outputs?
No. GPT-4o Mini TTS does not support tool calling, so it cannot invoke external tools or functions.
What inputs and outputs does GPT-4o Mini TTS support?
GPT-4o Mini TTS is a audio speech model. See the specifications section above for its exact supported input and output modalities.
How do I use GPT-4o Mini TTS 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/gpt-4o-mini-tts-2025-12-15".
When was GPT-4o Mini TTS released?
GPT-4o Mini TTS was released on August 30, 2026.
Where is the GPT-4o Mini TTS 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 GPT-OSS 120B 1 (nrouter.ai/models/gpt-oss-120b-1), GPT-6.1 Sol (nrouter.ai/models/gpt-6.1-sol), GPT-5.2 Pro (nrouter.ai/models/gpt-5.2-pro-2025-12-11), GPT Audio 1.5 (nrouter.ai/models/gpt-audio-1.5).