OpenAI model

TTS 1 HD API

openai/tts-1-hd converts text to speech at $0.30 per 10,000 input characters — double the standard tts-1 id's $0.15 on the same unit. Token prices do not apply and no context window is published. Choose it when the standard tier's output is not good enough and the 2x price is acceptable.

Read quickstartEstimate cost
OpenAIPlatform curatedCatalog
Speech price$0.3 / 10k chars
BillingPer 10k input characters
Context length— tokens
Max output8.2k tokens

What is TTS 1 HD API in NextModel?

openai/tts-1-hd converts text to speech at $0.30 per 10,000 input characters — double the standard tts-1 id's $0.15 on the same unit. Token prices do not apply and no context window is published. Choose it when the standard tier's output is not good enough and the 2x price is acceptable.

TTS 1 HD via NextModel: context unpublished; $0.3 / 10k chars in / — out per 1M tokens.

Best use cases

  • Speech output where the hd tier's fidelity matters more than the 2x price.
  • Workloads already costing $0.30 per 10k input characters into their unit economics.
  • A/B checks between hd and standard through the same OpenAI-compatible endpoint.

When not to use

  • Cost-sensitive volume: tts-1 is $0.15 per 10k characters.
  • You expect per-token billing — this id is billed per input characters.
  • You need a published context window: none is published for this id.

OpenAI-compatible code example

request.sh
curl https://api.nextmodel.app/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $NEXTMODEL_API_KEY" \
  -d '{"model":"openai/tts-1-hd","messages":[{"role":"user","content":"Reply with OK."}]}'

Switching models only changes the model field.

Try it in the playground

Speech models use the chat shape for now - see the audio guide.

Similar alternatives

OpenAICatalog

GPT-5 Codex

GPT-5 Codex via NextModel: 400k-token context; $1.25 / 1M tokens in / $10 / 1M tokens out per 1M tokens. Capabilities: streaming.

$1.25 / 1M tokensInput$10 / 1M tokensOutput400kContext
Best forGeneral chat via OpenAI, API workloads
Streaming
Platform curatedCurated and maintained in the NextModel catalog
View details
OpenAICatalog

Text Embedding 3 Large

Text Embedding 3 Large via NextModel: context unpublished; $0.13 / 1M tokens in / $0 / 1M tokens out per 1M tokens. Capabilities: streaming.

$0.13 / 1M tokensInput—Output—Context
Best forGeneral chat via OpenAI, API workloads
Streaming
Platform curatedCurated and maintained in the NextModel catalog
View details
OpenAICatalog

Text Embedding 3 Small

Text Embedding 3 Small via NextModel: context unpublished; $0.02 / 1M tokens in / $0 / 1M tokens out per 1M tokens. Capabilities: streaming.

$0.02 / 1M tokensInput—Output—Context
Best forGeneral chat via OpenAI, API workloads
Streaming
Platform curatedCurated and maintained in the NextModel catalog
View details

Compare TTS 1 HD

TTS 1 HD vs GPT-5 CodexTTS 1 HD vs Text Embedding 3 LargeTTS 1 HD vs Text Embedding 3 SmallTTS 1 HD vs TTS 1TTS 1 HD vs Whisper Large V3 Turbo

Reading

Articles that explain TTS 1 HD

FAQ

TTS 1 HD API questions

What model id do I send for TTS 1 HD?

Send openai/tts-1-hd to https://api.nextmodel.app/v1 with your OpenAI SDK. If that id is missing from /v1/models, the page is stale.

How is TTS 1 HD billed?

$0.30 per 10,000 input characters — not per token.

Is HD worth 2x?

hd is $0.30 per 10k input characters versus tts-1's $0.15. The catalog publishes no fidelity measurement — A/B them on your own scripts before committing.

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