--- title: Inworld TTS 1.5 Max description: Highest-quality text-to-speech with under 200ms latency, emotion control, and 15-language support. image: https://edgetunnel-b2h.pages.dev/dev-products-preview.png --- > Documentation Index > Fetch the complete documentation index at: https://edgetunnel-b2h.pages.dev/ai/llms.txt > Use this file to discover all available pages before exploring further. [Skip to content](#%5Ftop) ![Inworld logo](https://edgetunnel-b2h.pages.dev/_astro/inworld.BDwMAXI2.svg) # Inworld TTS 1.5 Max Text-to-Speech • Inworld `inworld/tts-1.5-max` Highest-quality text-to-speech with under 200ms latency, emotion control, and 15-language support. | Model Info | | | ------------------- | --------------------------------------------------------------------------------------------------------------------- | | Terms and License | [link ↗](https://inworld.ai/terms) | | More information | [link ↗](https://inworld.ai/) | | Zero data retention | Yes | | Pricing | [View pricing in the Cloudflare dashboard ↗](https://dash.cloudflare.com/?to=/:account/ai/models/inworld/tts-1.5-max) | ## Usage * [ TypeScript ](#tab-panel-840) * [ cURL ](#tab-panel-841) **TypeScript** ```ts const response = await env.AI.run( 'inworld/tts-1.5-max', { output_format: 'mp3', temperature: 1, text: 'Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.', timestamp_type: 'none', voice_id: 'Dennis', }, ) console.log(response) ``` ```bash curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "inworld/tts-1.5-max", "input": { "output_format": "mp3", "temperature": 1, "text": "Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.", "timestamp_type": "none", "voice_id": "Dennis" } }' ``` * [ Output ](#tab-panel-836) * [ Raw response ](#tab-panel-837) ```json { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-max/simple-speech.mp3" }, "state": "Completed" } ``` ## Examples **Slow Narration** — Slower speech for narration * [ TypeScript ](#tab-panel-844) * [ cURL ](#tab-panel-845) **TypeScript** ```ts const response = await env.AI.run( 'inworld/tts-1.5-max', { output_format: 'mp3', speaking_rate: 0.85, temperature: 1, text: 'In the beginning, the universe was a singularity of infinite density. Then, in a fraction of a second, it expanded into everything we know today.', timestamp_type: 'none', voice_id: 'Dennis', }, ) console.log(response) ``` ```bash curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "inworld/tts-1.5-max", "input": { "output_format": "mp3", "speaking_rate": 0.85, "temperature": 1, "text": "In the beginning, the universe was a singularity of infinite density. Then, in a fraction of a second, it expanded into everything we know today.", "timestamp_type": "none", "voice_id": "Dennis" } }' ``` * [ Output ](#tab-panel-838) * [ Raw response ](#tab-panel-839) ```json { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-max/slow-narration.mp3" }, "state": "Completed" } ``` **High Quality Audio** — Higher sample rate for studio quality * [ TypeScript ](#tab-panel-848) * [ cURL ](#tab-panel-849) **TypeScript** ```ts const response = await env.AI.run( 'inworld/tts-1.5-max', { output_format: 'mp3', sample_rate: 48000, temperature: 1, text: 'This recording is generated at studio quality for the best possible listening experience.', timestamp_type: 'none', voice_id: 'Dennis', }, ) console.log(response) ``` ```bash curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "inworld/tts-1.5-max", "input": { "output_format": "mp3", "sample_rate": 48000, "temperature": 1, "text": "This recording is generated at studio quality for the best possible listening experience.", "timestamp_type": "none", "voice_id": "Dennis" } }' ``` * [ Output ](#tab-panel-842) * [ Raw response ](#tab-panel-843) ```json { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-max/high-quality-audio.mp3" }, "state": "Completed" } ``` **With Text Normalization** — Expand numbers and abbreviations before synthesis * [ TypeScript ](#tab-panel-850) * [ cURL ](#tab-panel-851) **TypeScript** ```ts const response = await env.AI.run( 'inworld/tts-1.5-max', { apply_text_normalization: true, output_format: 'mp3', temperature: 1, text: 'The meeting is at 3:30 PM on Jan 15th, 2026. Please confirm by calling 555-0123.', timestamp_type: 'none', voice_id: 'Dennis', }, ) console.log(response) ``` ```bash curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "inworld/tts-1.5-max", "input": { "apply_text_normalization": true, "output_format": "mp3", "temperature": 1, "text": "The meeting is at 3:30 PM on Jan 15th, 2026. Please confirm by calling 555-0123.", "timestamp_type": "none", "voice_id": "Dennis" } }' ``` * [ Output ](#tab-panel-846) * [ Raw response ](#tab-panel-847) ```json { "gatewayMetadata": { "keySource": "Unified" }, "result": { "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-max/with-text-normalization.mp3" }, "state": "Completed" } ``` ## Parameters * [ Input ](#tab-panel-852) * [ Output ](#tab-panel-853) text `string`requiredmaxLength: 2000The text to be synthesized into speech. Maximum input of 2,000 characters. voice\_id `string`requireddefault: Dennisenum: Loretta, Darlene, Marlene, Hank, Evelyn, Celeste, Pippa, Tessa, Liam, Callum, Hamish, Abby, Graham, Rupert, Mortimer, Snik, Anjali, Saanvi, Arjun, Claire, Oliver, Simon, Elliot, James, Serena, Gareth, Vinny, Lauren, Jessica, Ethan, Tyler, Jason, Chloe, Veronica, Victoria, Miranda, Sebastian, Victor, Malcolm, Nate, Brian, Amina, Kelsey, Derek, Evan, Kayla, Jake, Grant, Tristan, Nadia, Selene, Marcus, Riley, Damon, Cedric, Mia, Naomi, Jonah, Levi, Avery, Brandon, Conrad, Bianca, Lucian, Trevor, Alex, Ashley, Craig, Deborah, Dennis, Edward, Elizabeth, Hades, Julia, Pixie, Mark, Olivia, Priya, Ronald, Sarah, Shaun, Theodore, Timothy, Wendy, Dominus, Hana, Clive, Carter, Blake, Luna, Reed, Duncan, Felix, Eleanor, SophieThe ID of the voice to use for synthesizing speech. Defaults to Dennis. output\_format `string`requireddefault: mp3enum: mp3, opus, wav, flacThe output format for the audio. Supported formats are mp3, opus, wav, and flac. Defaults to mp3. bit\_rate `integer`minimum: \-9007199254740991maximum: 9007199254740991Bits per second of the audio. Only for compressed audio formats (mp3, opus). The default is 128,000. sample\_rate `integer`minimum: \-9007199254740991maximum: 9007199254740991The synthesis sample rate in hertz. Accepts: 8000, 16000, 22050, 24000, 32000, 44100, 48000\. The default is 48,000. speaking\_rate `number`minimum: 0.5maximum: 1.5Speaking rate/speed, in the range \[0.5, 1.5\]. The default is 1.0\. We recommend using values above 0.8 to ensure high quality. temperature `number`requireddefault: 1minimum: 0.01maximum: 2Determines the degree of randomness when sampling audio tokens. Defaults to 1.0\. Accepts values between 0 (exclusive) and 2 (inclusive). Higher values = more expressive, lower values = more deterministic. timestamp\_type `string`requireddefault: noneenum: none, word, characterControls timestamp metadata returned with the audio. "word" returns word-level timing, "character" returns character-level timing. Note: adds latency. Defaults to none. apply\_text\_normalization `boolean`When enabled, text normalization expands numbers, dates, times, and abbreviations before converting to speech. Turning this off may reduce latency. audio `string`URL to the generated audio file ## API Schemas (Raw) Input [ ](https://edgetunnel-b2h.pages.dev/ai/models/inworld/tts-1.5-max/schema-input.json "Open") [ ](https://edgetunnel-b2h.pages.dev/ai/models/inworld/tts-1.5-max/schema-input.json "Download") Output [ ](https://edgetunnel-b2h.pages.dev/ai/models/inworld/tts-1.5-max/schema-output.json "Open") [ ](https://edgetunnel-b2h.pages.dev/ai/models/inworld/tts-1.5-max/schema-output.json "Download") ```json {"@context":"https://schema.org","@type":"TechArticle","@id":"https://edgetunnel-b2h.pages.dev/ai/models/inworld/tts-1.5-max/#page","headline":"Inworld TTS 1.5 Max (Inworld) · Cloudflare AI docs · Cloudflare AI docs","description":"Highest-quality text-to-speech with under 200ms latency, emotion control, and 15-language support.","url":"https://edgetunnel-b2h.pages.dev/ai/models/inworld/tts-1.5-max/","inLanguage":"en","image":"https://edgetunnel-b2h.pages.dev/dev-products-preview.png","publisher":{"@type":"Organization","name":"Cloudflare","url":"https://www.cloudflare.com/"},"isPartOf":{"@type":"WebSite","@id":"https://edgetunnel-b2h.pages.dev/#website","name":"Cloudflare Docs","url":"https://edgetunnel-b2h.pages.dev/"}} {"@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"}}]} ```