Browse ModelsInworldInworld 1.5 Mini Text To Speech

Inworld 1.5 Mini Text To Speech

Inworld 1.5 Mini Text To Speech

Playground

Try it on WavespeedAI!

Inworld 1.5 Mini delivers high-quality text-to-speech synthesis with 56+ multilingual voices, adjustable speaking rate, and natural-sounding audio output. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

Inworld 1.5 Mini Text-to-Speech

Inworld 1.5 Mini is a lightweight, ultra-affordable text-to-speech model that converts written text into natural speech. It offers the same voice selection, speaking rate, and expressiveness controls as the Max model — at half the cost. Perfect for high-volume workflows, prototyping, and budget-conscious production.


Why Choose This?

  • Ultra-low cost Just $0.005 per 1,000 characters — the most affordable option for text-to-speech at scale.

  • Voice selection Choose from a library of distinct voice identities to match your brand, character, or use case.

  • Speaking rate control Adjust the speed of speech to suit narration, dialogue, announcements, or any delivery style.

  • Temperature control Fine-tune expressiveness — lower values for consistent delivery; higher values for more dynamic, varied speech.

  • Fast processing Lightweight architecture delivers quick turnaround, ideal for real-time or high-volume pipelines.


Parameters

ParameterRequiredDescription
textYesThe text content to convert to speech
voice_idNoVoice preset to use (e.g., Hades)
speaking_rateNoSpeed of speech (default: 1)
temperatureNoExpressiveness level (default: 1)

How to Use

  1. Enter your text — type or paste the content you want converted to speech.
  2. Select a voice — choose a voice preset from the voice_id dropdown.
  3. Adjust speaking rate — slide to control how fast or slow the speech is delivered.
  4. Adjust temperature — slide to control the expressiveness and variation in delivery.
  5. Run — submit and download the generated audio.

Pricing

CharactersCost
Up to 1,000$0.005
Up to 2,000$0.010
Up to 5,000$0.025
Up to 10,000$0.050

Billing Rules

  • Rate: $0.005 per 1,000 characters
  • Rounding: character count is rounded up to the next 1,000

Best Use Cases

  • High-Volume Production — Generate large batches of audio at minimal cost.
  • Prototyping & Testing — Quickly preview voiceovers before committing to final production.
  • Chatbots & Virtual Assistants — Add voice output to conversational AI at scale.
  • Content Accessibility — Convert written content to audio affordably for wider audiences.
  • Game & App Dialogue — Generate character voice lines for interactive experiences on a budget.

Pro Tips

  • Use Mini for drafting and iteration, then switch to Max for final production if higher quality is needed.
  • Keep speaking_rate around 1 for natural pacing; adjust lower for dramatic reads, higher for quick announcements.
  • Lower temperature gives more predictable, consistent output — great for automated systems.
  • Break long texts into logical paragraphs for better pacing and natural pauses.

Notes

  • Text is the only required field.
  • Billing is based on character count, rounded up to the nearest 1,000.
  • For maximum voice quality, consider Inworld 1.5 Max.

Authentication

For authentication details, please refer to the Authentication Guide.

API Endpoints

Submit Task & Query Result


# Submit the task
curl --location --request POST "https://api.wavespeed.ai/api/v3/inworld/1.5-mini/text-to-speech" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}" \
--data-raw '{
    "voice_id": "Alex",
    "speaking_rate": 1,
    "temperature": 1
}'

# Get the result
curl --location --request GET "https://api.wavespeed.ai/api/v3/predictions/${requestId}/result" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}"

Parameters

Task Submission Parameters

Request Parameters

ParameterTypeRequiredDefaultRangeDescription
textstringYes--Styling instructions on how to synthesize the content in the text field.
voice_idstringNoAlexAlex, Ashley, Craig, Deborah, Dennis, Edward, Elizabeth, Hades, Julia, Pixie, Mark, Olivia, Priya, Ronald, Sarah, Shaun, Theodore, Timothy, Wendy, Dominus, Hana, Clive, Carter, Blake, Luna, Yichen, Xiaoyin, Xinyi, Jing, Erik, Katrien, Lennart, Lore, Alain, Hélène, Mathieu, Étienne, Johanna, Josef, Gianni, Orietta, Asuka, Satoshi, Hyunwoo, Minji, Seojun, Yoona, Szymon, Wojciech, Heitor, Maitê, Diego, Lupita, Miguel, Rafael, Svetlana, Elena, Dmitry, Nikolai, Riya, Manoj, Yael, Oren, Nour, OmarThe voice to use for speech generation.
speaking_ratenumberNo10.5 ~ 1.5The speed of speaking.
temperaturenumberNo10.7 ~ 1.5The temperature to use for the generation. A higher value means more randomness in the output.

Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
data.idstringUnique identifier for the prediction, Task Id
data.modelstringModel ID used for the prediction
data.outputsarrayArray of URLs to the generated content (empty when status is not completed)
data.urlsobjectObject containing related API endpoints
data.urls.getstringURL to retrieve the prediction result
data.has_nsfw_contentsarrayArray of boolean values indicating NSFW detection for each output
data.statusstringStatus of the task: created, processing, completed, or failed
data.created_atstringISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”)
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds

Result Request Parameters

ParameterTypeRequiredDefaultDescription
idstringYes-Task ID

Result Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
dataobjectThe prediction data object containing all details
data.idstringUnique identifier for the prediction, the ID of the prediction to get
data.modelstringModel ID used for the prediction
data.outputsstringArray of URLs to the generated content (empty when status is not completed).
data.urlsobjectObject containing related API endpoints
data.urls.getstringURL to retrieve the prediction result
data.statusstringStatus of the task: created, processing, completed, or failed
data.created_atstringISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”)
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds
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