--- title: TTS-1 description: OpenAI's text-to-speech model optimized for real-time use with low latency. image: https://developers.cloudflare.com/dev-products-preview.png --- > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/ai/llms.txt > Use this file to discover all available pages before exploring further. [Skip to content](#%5Ftop) ![OpenAI logo](https://developers.cloudflare.com/_astro/openai.BI8PEEzI.svg) # TTS-1 Text-to-Speech • OpenAI `openai/tts-1` OpenAI's text-to-speech model optimized for real-time use with low latency. | Model Info | | | ------------------- | -------------------------------------------------------------------------------------------------------------- | | Terms and License | [link ↗](https://openai.com/policies/) | | More information | [link ↗](https://platform.openai.com/docs/guides/text-to-speech) | | Zero data retention | Yes | | Pricing | [View pricing in the Cloudflare dashboard ↗](https://dash.cloudflare.com/?to=/:account/ai/models/openai/tts-1) | ## Usage * [ TypeScript ](#tab-panel-1494) * [ cURL ](#tab-panel-1495) TypeScript ``` const response = await env.AI.run( 'openai/tts-1', { response_format: 'mp3', speed: 1, text: 'Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.', voice: 'alloy', },)console.log(response) ``` Terminal window ``` curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "openai/tts-1", "input": { "response_format": "mp3", "speed": 1, "text": "Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.", "voice": "alloy" }}' ``` * [ Output ](#tab-panel-1490) * [ Raw response ](#tab-panel-1491) ``` { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/simple-speech.mp3" }, "state": "Completed"} ``` ## Examples **Different Voice** — Use the Nova voice for a different tone * [ TypeScript ](#tab-panel-1498) * [ cURL ](#tab-panel-1499) TypeScript ``` const response = await env.AI.run( 'openai/tts-1', { response_format: 'mp3', speed: 1, text: 'The weather today is sunny with a high of 72 degrees. Perfect for a walk in the park.', voice: 'nova', },)console.log(response) ``` Terminal window ``` curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "openai/tts-1", "input": { "response_format": "mp3", "speed": 1, "text": "The weather today is sunny with a high of 72 degrees. Perfect for a walk in the park.", "voice": "nova" }}' ``` * [ Output ](#tab-panel-1492) * [ Raw response ](#tab-panel-1493) ``` { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/different-voice.mp3" }, "state": "Completed"} ``` **Narration** — Slower narration style with the Onyx voice * [ TypeScript ](#tab-panel-1502) * [ cURL ](#tab-panel-1503) TypeScript ``` const response = await env.AI.run( 'openai/tts-1', { response_format: 'mp3', speed: 0.85, text: 'In the beginning, the universe was a singularity of infinite density. Then, in a fraction of a second, it expanded into everything we know today.', voice: 'onyx', },)console.log(response) ``` Terminal window ``` curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "openai/tts-1", "input": { "response_format": "mp3", "speed": 0.85, "text": "In the beginning, the universe was a singularity of infinite density. Then, in a fraction of a second, it expanded into everything we know today.", "voice": "onyx" }}' ``` * [ Output ](#tab-panel-1496) * [ Raw response ](#tab-panel-1497) ``` { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/narration.mp3" }, "state": "Completed"} ``` **Echo Voice** — Use the Echo voice for a deeper tone * [ TypeScript ](#tab-panel-1506) * [ cURL ](#tab-panel-1507) TypeScript ``` const response = await env.AI.run( 'openai/tts-1', { response_format: 'mp3', speed: 1, text: 'Welcome back to the podcast. Today we are going to talk about the future of artificial intelligence and its impact on creative work.', voice: 'echo', },)console.log(response) ``` Terminal window ``` curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "openai/tts-1", "input": { "response_format": "mp3", "speed": 1, "text": "Welcome back to the podcast. Today we are going to talk about the future of artificial intelligence and its impact on creative work.", "voice": "echo" }}' ``` * [ Output ](#tab-panel-1500) * [ Raw response ](#tab-panel-1501) ``` { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/echo-voice.mp3" }, "state": "Completed"} ``` **Fast Playback** — Speed up speech for quick listening * [ TypeScript ](#tab-panel-1508) * [ cURL ](#tab-panel-1509) TypeScript ``` const response = await env.AI.run( 'openai/tts-1', { response_format: 'mp3', speed: 1.5, text: 'This is a fast-paced summary of the key findings from the quarterly report. Revenue is up fifteen percent, user growth exceeded expectations, and infrastructure costs remain stable.', voice: 'shimmer', },)console.log(response) ``` Terminal window ``` curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "openai/tts-1", "input": { "response_format": "mp3", "speed": 1.5, "text": "This is a fast-paced summary of the key findings from the quarterly report. Revenue is up fifteen percent, user growth exceeded expectations, and infrastructure costs remain stable.", "voice": "shimmer" }}' ``` * [ Output ](#tab-panel-1504) * [ Raw response ](#tab-panel-1505) ``` { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/fast-playback.mp3" }, "state": "Completed"} ``` ## Parameters * [ Input ](#tab-panel-1510) * [ Output ](#tab-panel-1511) text `string`requiredmaxLength: 4096The text to generate audio for. Maximum length is 4096 characters. voice `string`requireddefault: alloyenum: alloy, echo, fable, onyx, nova, shimmerThe voice to use when generating the audio. Defaults to alloy. response\_format `string`requireddefault: mp3enum: mp3, opus, wav, aac, flacThe output format for the audio. Supported formats are mp3, opus, wav, aac and flac. speed `number`requireddefault: 1minimum: 0.25maximum: 4The speed of the generated audio. Select a value from 0.25 to 4.0\. 1.0 is the default. audio `string`URL to the generated audio file ## API Schemas (Raw) Input [ ](https://developers.cloudflare.com/ai/models/openai/tts-1/schema-input.json "Open") [ ](https://developers.cloudflare.com/ai/models/openai/tts-1/schema-input.json "Download") Output [ ](https://developers.cloudflare.com/ai/models/openai/tts-1/schema-output.json "Open") [ ](https://developers.cloudflare.com/ai/models/openai/tts-1/schema-output.json "Download") ```json {"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/ai/models/openai/tts-1/#page","headline":"TTS-1 (OpenAI) · Cloudflare AI docs · Cloudflare AI docs","description":"OpenAI's text-to-speech model optimized for real-time use with low latency.","url":"https://developers.cloudflare.com/ai/models/openai/tts-1/","inLanguage":"en","image":"https://developers.cloudflare.com/dev-products-preview.png","publisher":{"@type":"Organization","name":"Cloudflare","url":"https://www.cloudflare.com/"},"isPartOf":{"@type":"WebSite","@id":"https://developers.cloudflare.com/#website","name":"Cloudflare Docs","url":"https://developers.cloudflare.com/"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/ai/","name":"AI"}},{"@type":"ListItem","position":3,"item":{"@id":"/ai/models/","name":"Models"}}]} ```