As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/m/tts-1/

# TTS-1 / TTS-1 HD

OpenAI, OpenAI TTS family. Status: deprecated. Type: speech and audio. Released: 2023-11-06.

## How to call it

| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| OpenAI API | `tts-1` | https://api.openai.com/v1/audio/speech | https://developers.openai.com/api/docs/models/tts-1 |
| OpenAI API | `tts-1-hd` | https://api.openai.com/v1/audio/speech | https://developers.openai.com/api/docs/models/tts-1-hd |

## Pricing

- Per 1M characters: $15
- Unit as published: USD per 1M characters for tts-1; tts-1-hd $30 per 1M characters
- Source: https://developers.openai.com/api/docs/pricing
- Last checked: 2026-10-15

## Specs

- Input: text
- Output: audio
- Context window: not published
- Max output: not published
- Open weights: no
- Licence: proprietary

## Where it stands

- Newer speech and audio models in the registry since its release: 107. The 5 newest:
  - NVIDIA Nemotron 3.5 Transcribe (30B-A4B) (2026-10-28) https://postcutoff.com/m/nemotron-3-5-transcribe/
  - Hy-SimulMT-30B-A3B (2026-10-22) https://postcutoff.com/m/hy-simulmt-30b-a3b/
  - Eleven Realtime v1 Max / Mini (2026-10-20) https://postcutoff.com/m/eleven-realtime-v1-max/
  - Voxtral Mini Transcribe 3 (+ Mini Transcribe Realtime 3) (2026-10-20) https://postcutoff.com/m/voxtral-mini-transcribe-3/
  - Voxtral Small Transcribe 3 (2026-10-20) https://postcutoff.com/m/voxtral-small-transcribe-3/
- Before it from OpenAI: Whisper (whisper-1 API) (2023-03-01) https://postcutoff.com/m/whisper-1/
- After it from OpenAI: GPT-4o Transcribe / Mini Transcribe / Transcribe Diarize (2025-03-20) https://postcutoff.com/m/gpt-4o-transcribe/
- Closed weights; access is hosted only.

## What stands out

- Low-latency preset-voice TTS: tts-1 optimised for real-time synthesis; tts-1-hd for higher quality at twice the price. Source: https://developers.openai.com/api/docs/models/tts-1

## Notes

Deprecated 2026-10-01 together with tts-1-hd and the gpt-4o-mini-tts snapshots: removal from the API on Jan 6 2027, replacement gpt-realtime-2.1-mini (https://developers.openai.com/api/docs/deprecations). Earlier note: no longer shown in the models overview; gpt-4o-mini-tts is the current, instruction-steerable replacement. Release date = OpenAI DevDay 2023 (from memory, not re-verified today).

Sources:
- https://developers.openai.com/api/docs/models/tts-1
- https://developers.openai.com/api/docs/pricing

Model page: https://postcutoff.com/m/tts-1/