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OpenAI Text-to-Speech
What OpenAI Text-to-Speech is
OpenAI Text-to-Speech converts text into spoken audio through an API, with GPT-4o Mini TTS supporting controls for accent, emotional range, intonation, impressions, speed, tone, and whispering. The guide gives examples including blog narration, multilingual spoken audio, and realtime output using streaming. Chunked audio streaming can start playback before generation finishes. The default output is MP3; supported formats also include Opus, AAC, FLAC, WAV, and PCM. The guide lists 13 built-in voices and recommends marin or cedar for quality; voices are currently optimized for English. Commercial use and voice cloning are supported, with custom voices subject to eligibility and recording requirements. The model page lists a 2,000-token input limit, while the guide states a 4,096 maximum input. TTS-1 costs $15 a month, and TTS-1 HD costs $30 a month. GPT-4o Mini TTS API usage costs $0.60 a month per 1 million text input tokens, with audio output billed separately at $12.00 per 1 million audio tokens; no free tier is supported.
Who it suits
It suits developers building speech generation into software through an API, including workflows that use streaming or adjustable speech characteristics. Teams considering generated voices must disclose to end users that the voice is AI-generated.
What it does well
- Supports 57 languages and multiple audio export formats.
- Streaming can begin playback before generation completes.
- Speech controls include tone, speed, and intonation.
- Supports commercial use and eligible custom voices.
- API platform data is encrypted in transit and at rest.
What to know first
- No free plan or free tier is supported.
- GPT-4o Mini TTS input maximum is 2,000 tokens on the model page.
- Audio output is billed separately from text input.
- Built-in voices are currently optimized for English.
Limits
GPT-4o Mini TTS API usage is billed at $0.60 per 1M text input tokens, with audio output billed separately at $12.00 per 1M audio tokens; its maximum input is 2,000 tokens and free tier is unsupported. The listed TTS-1 and TTS-1 HD plans cost $15 a month and $30 a month.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| TTS-1 | Text-to-speech model optimized for speed · Speech generation through the Audio API | $15 a month |
| TTS-1 HD | Higher-quality text-to-speech model | $30 a month |
| GPT-4o Mini TTS API usage | per 1M text input tokens; audio output billed separately at $12.00 per 1M audio tokens · maximum 2,000 input tokens · Free tier not supported | $0.60 a month |
As developers.openai.com lists them, read 20 Sept 2026. The maker's own page has the final word.
Getting started
- Open the developer text-to-speech guide
- Choose an OpenAI speech plan or API usage billing
- Use the speech generation API endpoint
- Integrate with an OpenAI SDK or the command line
- Select a voice, output format, and speech instructions
- Disclose to listeners that the voice is AI-generated
Verdict
OpenAI Text-to-Speech offers API-based speech generation with streaming, multiple formats, and adjustable delivery. Pricing and input limits differ by listed offering, and generated voices require clear user disclosure.
Questions
Is OpenAI Text-to-Speech free?
No. It is listed as paid, with no free plan. GPT-4o Mini TTS API usage has no supported free tier.
Which platforms does it support?
The platform is an API deployed in the cloud.
What audio formats can it export?
MP3 is the default. Opus, AAC, FLAC, WAV, and PCM are also supported.
How many languages and voices are available?
The service supports 57 languages and lists 13 built-in voices. Those voices are currently optimized for English.
Can it clone voices?
Yes. An approved custom voice can be created from a speaker’s consent recording and matching audio sample, subject to eligibility and recording requirements.
What are the listed plans?
TTS-1 costs $15 a month, TTS-1 HD costs $30 a month, and GPT-4o Mini TTS API usage costs $0.60 per 1M text input tokens with separate audio charges.
Facts from OpenAI Text-to-Speech's own pages
- API access
- Yes · developers.openai.com, 20 Sept 2026
- API integration
- The guide provides examples using OpenAI SDKs for JavaScript, Python, Go, Java, Ruby, and the command line. · developers.openai.com, 7 Oct 2026
- Commercial use
- Yes · developers.openai.com, 20 Sept 2026
- Custom voices
- An approved custom voice can be created from a speaker’s consent recording and matching audio sample, subject to eligibility and recording requirements. · developers.openai.com, 7 Oct 2026
- Data use and retention
- OpenAI says API Platform data is not used for model training by default and that API inputs and outputs may be retained for up to 30 days, with zero data retention available for eligible endpoints and qualifying use cases. · openai.com, 7 Oct 2026
- Export formats
- mp3,opus,aac,flac,wav,pcm · developers.openai.com, 20 Sept 2026
- Languages
- 57 · developers.openai.com, 20 Sept 2026
- Languages
- The TTS model can generate spoken audio in the languages listed in the guide by supplying text in the desired language. · developers.openai.com, 7 Oct 2026
- Maker
- OpenAI describes itself as an AI research and deployment company. · openai.com, 7 Oct 2026
- Maximum input
- 4096 · developers.openai.com, 20 Sept 2026
- Model input limit
- The model page states a maximum input size of 2,000 tokens. · developers.openai.com, 7 Oct 2026
- Output formats
- The default response format is MP3, and supported formats include Opus, AAC, FLAC, WAV, and PCM. · developers.openai.com, 7 Oct 2026
- Platforms
- api · developers.openai.com, 20 Sept 2026
- Security
- OpenAI says API Platform data is encrypted at rest with AES-256 and in transit with TLS 1.2 or higher, and that the API Platform is SOC 2 Type 2 audited. · openai.com, 7 Oct 2026
- Speech controls
- With gpt-4o-mini-tts, instructions can control accent, emotional range, intonation, impressions, speech speed, tone, and whispering. · developers.openai.com, 7 Oct 2026
- Speech uses
- The guide lists narrating written blog posts, producing spoken audio in multiple languages, and realtime audio output using streaming as example uses. · developers.openai.com, 7 Oct 2026
- Streaming
- Speech API chunked audio streaming lets playback begin before the complete file is generated. · developers.openai.com, 7 Oct 2026
- User disclosure
- OpenAI usage policies require clear disclosure to end users that the TTS voice they hear is AI-generated and not a human voice. · developers.openai.com, 7 Oct 2026
- Voice cloning
- Yes · developers.openai.com, 20 Sept 2026
- Voices
- The guide lists 13 built-in voices and recommends marin or cedar for best quality; voices are currently optimized for English. · developers.openai.com, 7 Oct 2026
- What it does
- The GPT-4o Mini TTS model converts text into natural sounding spoken text through the speech generation API endpoint. · developers.openai.com, 7 Oct 2026
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