[OpenAI](/ai-gateway/models/labs/openai) # TTS-1 HD TTS-1 HD is the quality-optimized variant of OpenAI's text-to-speech family, generating more polished, natural-sounding audio than `tts-1` for narration and produced content. Your use is subject to OpenAI's [Terms](https://openai.com/policies/terms-of-use) & [Privacy](https://openai.com/policies/privacy-policy) Policies. Speech [Use with AI Gateway](https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Futm_source%3Dgateway-model-page%26utm_campaign%3Dai-gateway-models&title=Get+Started+with+Vercel+AI+Gateway) [View docs](https://vercel.com/docs/ai-gateway) ``` 1import { experimental_generateSpeech as generateSpeech } from 'ai'; 2import { gateway } from '@ai-sdk/gateway'; 3import { writeFile } from 'node:fs/promises'; 4 5const result = await generateSpeech({ 6 model: gateway.speechModel('openai/tts-1-hd'), 7 text: 'Hello from the Vercel AI Gateway!', 8 voice: 'alloy', 9}); 10 11await writeFile('speech.mp3', result.audio.uint8Array); ``` [Read docs](https://vercel.com/docs/ai-gateway/sdks-and-apis/ai-sdk) [Overview](/ai-gateway/models/tts-1-hd) [About](/ai-gateway/models/tts-1-hd/about) [Providers](/ai-gateway/models/tts-1-hd/providers) [Similar](/ai-gateway/models/tts-1-hd/similar) [FAQ](/ai-gateway/models/tts-1-hd/faq) ## [Copy link to heading](#playground)Playground Try out TTS-1 HD by OpenAI. Usage is billed to your team at API rates. Free users (those who haven't made a payment) get $5 of credits every 30 days. ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75)TTS-1 HD Text The text the model will read aloud. Voice AlloyEchoFableOnyxNovaShimmer ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=96&q=75) Your generated audio will appear here ## [Copy link to heading](#providers)Providers Route requests across multiple providers. Copy a provider slug to set your preference. Visit the [docs](/docs/ai-gateway/provider-options) for more info. Using a provider means you agree to their terms, listed under Legal. | Provider | | --- | | Input | Capabilities | ZDR | No Training | Release Date | | | --- | --- | --- | --- | --- | --- | | ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) [OpenAI](/ai-gateway/models/providers/openai) Legal:[Terms](https://openai.com/policies/terms-of-use)•[Privacy](https://openai.com/policies/privacy-policy) | $30/M chars | | | | 11/06/2023 | | | --- | --- | --- | --- | --- | --- | --- | ## [Copy link to heading](#more-models-by-openai)More models by OpenAI All Text Code | Model | | --- | | Context | Latency | Throughput | Input | Output | Cache | Web Search | Capabilities | Providers | ZDR | No Training | Release Date | | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) [openai/gpt-5.6-luna](/ai-gateway/models/gpt-5.6-luna) | 1.1M | 1.5s | 242tps | $1/M$0.20/M Fast $0.40/M+1 more | $6/M$1.20/M Fast $2.40/M+1 more | Read: $0.1/M$0.02/M+1 more Write: $1.25/M$0.25/M+1 more | $10/K \+ input costs | +4 | ![azure logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fazure.png&w=48&q=75) ![bedrock logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Famazon%2520bedrock.png&w=48&q=75) ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) | | | 07/09/2026 | | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) [openai/gpt\-5.6-sol](/ai-gateway/models/gpt-5.6-sol) | 1.1M | 3.4s | 120tps | $4/M$2/M Fast $4/M+1 more | $20/M$10/M Fast $20/M+1 more | Read: $0.4/M$0.2/M+1 more Write: $5/M$2.5/M+1 more | $10/K \+ input costs | +4 | ![azure logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fazure.png&w=48&q=75) ![bedrock logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Famazon%2520bedrock.png&w=48&q=75) ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) | | | 07/09/2026 | | | ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) [openai/gpt-5.6-terra](/ai-gateway/models/gpt-5.6-terra) | 1.1M | 0.7s | 191tps | $2.50/M$2/M Fast $4/M+1 more | $15/M$12/M Fast $24/M+1 more | Read: $0.25/M$0.2/M+1 more Write: $3.13/M$2.5/M+1 more | $10/K \+ input costs | +4 | ![azure logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fazure.png&w=48&q=75) ![bedrock logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Famazon%2520bedrock.png&w=48&q=75) ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) | | | 07/09/2026 | | | ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) [openai/gpt-5.4](/ai-gateway/models/gpt-5.4) | 1.1M | 1.6s | 97tps | $2.50/MFast $5/M+1 more | $15/MFast $30/M+1 more | Read: $0.25/M+1 more Write: — | $10/K \+ input costs | +4 | ![azure logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fazure.png&w=48&q=75) ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) | | | 03/05/2026 | | | ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) [openai/gpt-5-nano](/ai-gateway/models/gpt-5-nano) | 400K | 4.2s | 237tps | $0.05/M | $0.40/M | Read:$0.01/M Write:— | $14/K \+ input costs | +3 | ![azure logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fazure.png&w=48&q=75) ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) | | | 08/07/2025 | | | ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) [openai/gpt-5-mini](/ai-gateway/models/gpt-5-mini) | 400K | 2.5s | 152tps | $0.25/MFast $0.45/M | $2/MFast $3.60/M | Read:$0.03/M Write:— | $14/K \+ input costs | +3 | ![azure logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fazure.png&w=48&q=75) ![openai logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Fopenai.png&w=48&q=75) | | | 08/07/2025 | | ## [Copy link to heading](#about-tts-1-hd)About TTS-1 HD TTS-1 HD debuted on November 6, 2023 at OpenAI's first DevDay as the high-definition counterpart to `tts-1`. The two models share the same interface and voices; the difference is the optimization target. `tts-1` favors real-time latency, while TTS-1 HD favors audio quality, producing more human-like speech in exchange for slower generation. The voice lineup includes `alloy`, `echo`, `fable`, `onyx`, `nova`, and `shimmer`. Output formats cover MP3, Opus, AAC, and FLAC, with FLAC useful when the audio feeds a post-production pipeline. Playback speed is adjustable from 0.25x to 4x. Pricing is per character of input text. Through AI Gateway, TTS-1 HD runs behind the same key, observability, and spend controls as the rest of your models. Call the AI SDK's `generateSpeech` function with this model's slug and store or serve the returned audio. ## [Copy link to heading](#what-to-consider-when-choosing-a-provider)What To Consider When Choosing a Provider - Configuration: Audio support on AI Gateway is in beta. Speech generation runs through the AI SDK's `generateSpeech` function with a text string, a voice, and an output format. For interactive features where response time shapes the experience, `tts-1` is the faster sibling; reserve TTS-1 HD for audio users will listen to more than once. - Zero Data Retention: Zero Data Retention is offered on a per-provider and model basis. See the [documentation](https://vercel.com/docs/ai-gateway/security-and-compliance/zdr) for details. - Authentication: AI Gateway authenticates requests using an [API key](https://vercel.com/docs/ai-gateway/authentication-and-byok#api-key-authentication) or [OIDC token](https://vercel.com/docs/ai-gateway/authentication-and-byok#oidc-token-authentication). You do not need to manage provider credentials directly. ## [Copy link to heading](#when-to-use-tts-1-hd)When to Use TTS-1 HD ### Best for - Video and course narration: Polished speech for content users watch and rewatch - Long-form audio content: Podcast-style output generated from written material - Pre-rendered voice lines: App and game audio produced ahead of time - Replayable produced audio: Deliverables where quality justifies slower generation ### Consider alternatives when - Live generated responses: `tts-1` is optimized for real-time use where latency shapes the experience - Two-way voice conversation: The gpt-realtime family handles live speech-to-speech directly - Volume-driven budgets: `tts-1` keeps per-character costs lower when its quality is sufficient ## [Copy link to heading](#conclusion)Conclusion TTS-1 HD closes the gap between generated speech and produced audio. Route narration and replayable content through TTS-1 HD on AI Gateway, and keep `tts-1` for the interactive paths where speed wins.