models/OpenAI/TTS-1 HD

OpenAI

TTS-1 HD

audio-tts

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OpenAI's high-definition text-to-speech model producing higher quality audio output.

MODALITIES

audio

RELEASED

2026-05-22

TTS-1 HD (openai/tts-1-hd) is a audio-tts model from OpenAI, released 2026-05-22. Pricing via AIgateway: $0.030 per 1K chars. Call it via https://api.aigateway.sh/v1/audio/speech — set model="openai/tts-1-hd". Best for: Voiceovers, IVR, Audiobooks.

model · openai/tts-1-hd

Use this model

model: openai/tts-1-hd

curl https://api.aigateway.sh/v1/audio/speech \
  -H "Authorization: Bearer $AIGATEWAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"openai/tts-1-hd","voice":"alloy","input":"Hello, world."}'

curl https://api.aigateway.sh/v1/audio/speech \ -H "Authorization: Bearer $AIGATEWAY_API_KEY" \ -H "Content-Type: application/json" \ -d '{"model":"openai/tts-1-hd","voice":"alloy","input":"Hello world."}'

Capabilities

Strengths

Natural speech synthesis

Use cases

VoiceoversIVRAudiobooks

Pricing

Per 1K chars$0.030

You pay pass-through · 5% applied at credit top-up, not per-call.

See API example →Compare API reference See usage ranking →

Collections

More audio models →More from OpenAI →Frontier models →Free-tier models →

API schema

Call TTS-1 HD from any OpenAI SDK

POST https://api.aigateway.sh/v1/audio/speech·Content-Type: application/json·Auth: Bearer sk-aig-...

Request body

json

{
  "model": "openai/tts-1-hd",
  "input": "Hello from AIgateway.",
  "voice": "alloy",
  "format": "mp3",        // mp3 | wav | flac | opus
  "speed": 1.0
}

Response

json

// Binary audio stream in the requested format (mp3 by default).
// Content-Type: audio/mpeg  (or audio/wav, audio/flac, audio/opus)
// Read the response body directly to a file.

Quickstart

from openai import OpenAI
client = OpenAI(base_url="https://api.aigateway.sh/v1", api_key="sk-aig-...")

r = client.audio.speech.create(model="openai/tts-1-hd", voice="alloy", input="Hello world.")
r.stream_to_file("out.mp3")

Errors

401authentication_errorInvalid or missing API key

402insufficient_creditsWallet empty (PAYG only)

404not_foundUnknown model or endpoint

429rate_limit_errorOver per-minute limit — see Retry-After header

500server_errorUpstream provider failed (retryable)

503service_unavailableUpstream saturated (retryable)

Full docs →API reference →OpenAPI spec →llms.txt →

Frequently asked questions

What is TTS-1 HD?

OpenAI's high-definition text-to-speech model producing higher quality audio output. It is a audio-tts model from OpenAI, accessible via AIgateway's OpenAI-compatible API at slug openai/tts-1-hd.

How much does TTS-1 HD cost via AIgateway?

Pass-through pricing plus a 5% platform fee applied at top-up. See the pricing panel on this page for exact rates.

How do I call TTS-1 HD from my code?

Point the OpenAI SDK at https://api.aigateway.sh/v1 with your AIgateway key and set model to "openai/tts-1-hd". The request and response shapes match OpenAI exactly.

Does TTS-1 HD support streaming, tool calling, vision, and JSON mode?

Streaming — no. Tool calling — no. Vision — no. JSON mode — no. Prompt caching — no.

What are the best use cases for TTS-1 HD?

Voiceovers, IVR, Audiobooks. Key strengths: Natural speech synthesis.

Can I bring my own OpenAI API key (BYOK)?

Yes. Attach a OpenAI key in your AIgateway dashboard and this model flips to pass-through — you pay OpenAI directly and AIgateway waives the 5% platform fee on those calls.