Text to Speech
Converts written text into spoken audio output. Accepts up to 4096 tokens of input text per request.
OpenAI
TTS HD
TTS HD (model ID: tts-1-hd) is a text-to-speech model developed by OpenAI that converts written text into natural-sounding spoken audio. It accepts a text input of up to 4096 tokens and produces audio output in a variety of supported voices. TTS-1-HD is the quality-optimized variant in OpenAI's TTS model family, designed to produce higher-fidelity audio compared to the standard TTS-1 offering. The model is well-suited for applications that require clear, natural-sounding voice output, such as voice assistants, audiobook narration, accessibility tools, and content creation workflows. It supports multiple built-in voices and can output audio in formats including MP3, Opus, AAC, and FLAC. Developers access the model through OpenAI's API, and it is available on MindStudio without requiring separate API key management.
Unknown
N/A context
N/A output
Text to Speech
Multiple Voice Options
Audio Format Support
Quality-Optimized Output
API Integration
Model Overview
High-signal model metadata in a structured two-column overview table.
Provider
The entity that provides this model.
OpenAI
Input Context Window
The number of tokens supported by the input context window.
N/A
tokens
Maximum Output Tokens
The number of tokens that can be generated by the model in a single request.
N/A
tokens
Open Source
Whether the model's code is available for public use.
No
Release Date
When the model was first released.
Unknown
Knowledge Cut-off Date
When the model's knowledge was last updated.
Unknown
API Providers
The providers that offer this model. This is not an exhaustive list.
OpenAI API
Modalities
Types of data this model can process.
Text
Audio
What is TTS HD
A fuller summary of positioning, capabilities, and source-specific details for TTS HD.
TTS HD (model ID: tts-1-hd) is a text-to-speech model developed by OpenAI that converts written text into natural-sounding spoken audio. It accepts a text input of up to 4096 tokens and produces audio output in a variety of supported voices. TTS-1-HD is the quality-optimized variant in OpenAI's TTS model family, designed to produce higher-fidelity audio compared to the standard TTS-1 offering.
The model is well-suited for applications that require clear, natural-sounding voice output, such as voice assistants, audiobook narration, accessibility tools, and content creation workflows. It supports multiple built-in voices and can output audio in formats including MP3, Opus, AAC, and FLAC. Developers access the model through OpenAI's API, and it is available on MindStudio without requiring separate API key management.
Capabilities
What TTS HD supports
Multiple Voice Options
Supports a selection of built-in voices (e.g., alloy, echo, fable, onyx, nova, shimmer) to vary the tone and style of generated speech.
Audio Format Support
Outputs audio in multiple formats including MP3, Opus, AAC, and FLAC to suit different playback and storage requirements.
Quality-Optimized Output
The HD variant applies additional processing to produce higher-fidelity audio compared to the standard TTS-1 model, reducing artifacts in the output.
API Integration
Accessible via OpenAI's REST API, allowing developers to integrate speech synthesis directly into applications and pipelines.
Pricing for TTS HD
Primary API pricing shown in the same “quick compare” spirit as the reference page.
Input tokens
$30.00
Per million tokens
Output tokens
N/A
Per million tokens
API Access & Providers
Places where this model is available, based on the synced detail-page metadata.
OpenAI API
Configuration & Parameters
The configurable options currently documented for this model.
Voice
SelectVoice to use in TTS
Supported Request Parameters
Parameters currently listed by OpenRouter or the local catalog for this model.
Resources & Documentation
Official model cards, release notes, docs, and other references synced from the source page.
Community discussion
What people think about TTS HD
TTS HD discussions are most active in r/ChatGPT, r/ChatGPTPro, r/OpenWebUI. Top Reddit threads cluster around benchmark and model-comparison threads. The strongest match in this snapshot has 79 upvotes and 56 comments.
I generated the same text using both, and I can't tell the difference. Can you?
I wish I could attach my files in here :( I guess I can upload a YouTube video but I'm too lazy for that... Perhaps if I get a comment asking for it, I'll take the time to do it.
response = client.audio.speech.create(
model="tts-1", # vs tts-1-hd
voice="nova",
input=text
)
I do really like OpenAI’s text to speech hd model, it sounds great in many languages I tried.
However, I need to customize the voice for my project. Is there any good options?
FAQ
Common questions about TTS HD
What is the maximum input length for TTS HD?
TTS HD supports a context window of 4096 tokens per request, which corresponds to the maximum amount of text that can be converted to speech in a single API call.
What is the difference between TTS-1 and TTS-1-HD?
TTS-1-HD is the quality-optimized variant of OpenAI's text-to-speech model family. It is designed to produce higher-fidelity audio output, while TTS-1 is optimized for lower latency at the cost of some audio quality.
What audio formats does TTS HD support?
TTS HD can output audio in MP3, Opus, AAC, and FLAC formats, as documented in OpenAI's text-to-speech guide.
What voices are available with TTS HD?
OpenAI provides six built-in voices for TTS HD: alloy, echo, fable, onyx, nova, and shimmer. Each voice has a distinct tone and character.
Does TTS HD have a knowledge cutoff date?
TTS HD is a speech synthesis model and does not rely on a training knowledge cutoff in the same way language models do. The metadata lists the training date as not applicable.
How is TTS HD priced?
Pricing for TTS HD is set by OpenAI and is based on the number of characters processed. Refer to OpenAI's official pricing page for current rates, as pricing may change over time.
More models from OpenAI
Continue browsing adjacent models from the same provider.