Inworld 1.5 Max

Inworld 1.5 Max Text-to-Speech

Inworld 1.5 Max is a high-quality text-to-speech model that converts written text into natural, expressive speech. Choose from a variety of voice presets, fine-tune speaking rate and expressiveness with simple controls, and generate professional-grade audio in seconds — ideal for IVR systems, voiceovers, content creation, and accessibility.

• Need lower cost? Try Inworld 1.5 Mini Text-to-Speech

Why Choose This?

• Natural-sounding voices Multiple voice presets with realistic intonation, pacing, and emotion for lifelike speech output.

• Multilingual voice library 65+ voices across 14 languages including English, Chinese, Japanese, Korean, and more.

• 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, predictable delivery; higher values for more dynamic, varied speech.

• Affordable at scale Just $0.01 per 1,000 characters — professional quality at accessible pricing.

Parameters

Parameter	Required	Description
text	Yes	The text content to convert to speech
voice_id	No	Voice preset to use (see Available Voices below)
speaking_rate	No	Speed of speech (default: 1)
temperature	No	Expressiveness level (default: 1)

Available Voices

English

Voice ID	Description
Alex	Energetic and expressive mid-range male voice, with a mildly nasal quality
Ashley	A warm, natural female voice
Craig	Older British male with a refined and articulate voice
Deborah	Gentle and elegant female voice
Dennis	Middle-aged man with a smooth, calm and friendly voice
Edward	Male with a fast-talking, emphatic and streetwise tone
Elizabeth	Professional middle-aged woman, perfect for narrations and voiceovers
Hades	Commanding and gruff male voice, think an omniscient narrator or castle guard
Julia	Quirky, high-pitched female voice that delivers lines with playful energy
Pixie	High-pitched, childlike female voice with a squeaky quality
Mark	Energetic, expressive man with a rapid-fire delivery
Olivia	Young, British female with an upbeat, friendly tone
Priya	Even-toned female voice with an Indian accent
Ronald	Confident, British man with a deep, gravelly voice
Sarah	Fast-talking young adult woman, with a questioning and curious tone
Shaun	Friendly, dynamic male voice great for conversations
Theodore	Gravelly male voice, with a time-worn quality
Timothy	Lively, upbeat American male voice
Wendy	Posh, middle-aged British female voice
Dominus	Robotic, deep male voice with a menacing quality. Perfect for villains
Hana	Bright, expressive young female voice, perfect for storytelling and gaming
Clive	British-accented male voice with a calm, cordial quality
Carter	Energetic, mature radio announcer-style male voice
Blake	Rich, intimate male voice, perfect for audiobooks and romantic content
Luna	Calm, relaxing female voice, perfect for meditations and sleep stories

Chinese

Voice ID	Description
Yichen	A calm, flat young adult male Chinese voice
Xiaoyin	A youthful Chinese female voice with a gentle, sweet voice
Xinyi	A Chinese woman with a neutral tone, perfect for narrations
Jing	An energetic, fast-paced young Chinese female

Japanese

Voice ID	Description
Asuka	Friendly, young adult Japanese female voice
Satoshi	Dramatic, expressive male Japanese voice filled with energy

Korean

Voice ID	Description
Hyunwoo	Young adult Korean male voice
Minji	Energetic, friendly young Korean female voice
Seojun	Clear, deep mature Korean male voice
Yoona	Korean woman with a gentle, soothing voice

French

Voice ID	Description
Alain	Deep, smooth middle-aged male French voice. Composed and calm
Hélène	Middle-aged French woman, with a smooth, musical, and graceful voice
Mathieu	A French male voice carrying a nasal quality
Étienne	Calm young adult French male

German

Voice ID	Description
Johanna	A calm older German female with a low, smoky voice
Josef	An articulate German male voice with an announcer-like quality

Spanish

Voice ID	Description
Diego	Spanish-speaking male voice with a soothing, gentle quality
Lupita	Vibrant, energetic young Spanish-speaking female voice
Miguel	A calm adult Spanish-speaking male voice, perfect for storytelling
Rafael	Middle-aged Spanish-speaking male with a deep, composed voice

Portuguese

Voice ID	Description
Heitor	Composed Portuguese-speaking male voice with a neutral tone
Maitê	Middle-aged Portuguese-speaking female voice

Italian

Voice ID	Description
Gianni	Deep, smooth Italian male voice that speaks rapidly
Orietta	Calm adult female Italian voice, with a soothing cadence

Dutch

Voice ID	Description
Erik	Older Dutch male voice with a weathered edge
Katrien	Dutch woman with an expressive voice
Lennart	A confident Dutch male voice. Calm and relaxed
Lore	Clear, calm Dutch female voice, great for narrations

Polish

Voice ID	Description
Szymon	Polish adult male voice with a warm, friendly quality
Wojciech	A middle-aged Polish male voice

Russian

Voice ID	Description
Svetlana	Soft, high-pitched female voice, with a slightly breathy quality
Elena	Clear, mid-range female voice, with a neutral, informational tone
Dmitry	Deep, gravelly male voice, with a commanding and narrative tone
Nikolai	Deep, resonant male voice, with a clear, theatrical quality

Hindi

Voice ID	Description
Riya	Professional and clean female voice, polished and approachable
Manoj	Clear, professional Hindi male voice. Great for narrations

Hebrew

Voice ID	Description
Yael	Mid-range female Hebrew voice, suitable for narrations
Oren	Steady male Hebrew voice, great for podcasts and voiceovers

Arabic

Voice ID	Description
Nour	Polished female Arabic voice with a friendly tone
Omar	Bright, confident Arabic male voice, great for announcements

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

Characters	Cost
Up to 1,000	$0.01
Up to 2,000	$0.02
Up to 5,000	$0.05
Up to 10,000	$0.10

Billing Rules

• Rate: $0.01 per 1,000 characters
• Rounding: character count is rounded up to the next 1,000

Best Use Cases

• IVR & Phone Systems — Generate professional call menus, hold messages, and automated responses.
• Video Voiceovers — Add narration to marketing videos, tutorials, and presentations.
• Content Creation — Convert blog posts, articles, or scripts into audio for podcasts and social media.
• Accessibility — Provide audio versions of written content for visually impaired users.
• Game & App Dialogue — Create character voices for interactive experiences and virtual assistants.
• Multilingual Content — Create audio content in 14 languages from a single API.

Pro Tips

• Keep speaking_rate around 1 for natural-sounding narration; lower for dramatic reads, higher for fast announcements.
• Use lower temperature for consistent, predictable voiceovers (e.g., IVR); higher temperature for more expressive character dialogue.
• Break long texts into logical paragraphs for better pacing and natural pauses.
• Test different voice_id options to find the best match for your brand or character.
• Match voice language to your text language for best pronunciation and intonation.

Notes

• Text is the only required field.
• Billing is based on character count, rounded up to the nearest 1,000.
• Very long texts may take slightly longer to process.

Related Models

• Inworld 1.5 Mini Text-to-Speech — Same voices at $0.005 per 1,000 characters for budget-conscious workflows.