Lightning TTS v3.1
Next-Gen Text to Speech. Built for Real Conversation.
Faster than the blink of an eye. Designed for human conversation. 16 languages and growing.
Trusted by 100+ customers
Conversational
Customer Support
Assistant
Storytelling
Lightning TTS v3.1
Generated by Lightning TTS v3.1 44.1 kHz · <100ms
Lightning TTS v3.1
Generated by Lightning TTS v3.1 44.1 kHz · <100ms
Conversational
Customer Support
Assistant
Voice over
Performance that speaks for itself
Performance that speaks for itself
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Overall quality
Premium-tier listening experience
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kHz
Native sample rate
Highest fidelity among Lightning models
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Time To First Byte
One of the world's fastest models
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Naturalness
Predominantly human-like speech attribute
One model.
Every voice use case.
Use Lightning V3.1
in the context that matters to you.
Each card plays a short sample. Hear Lightning in the context that matters to you.
Conversational Agent
Natural interactions with humans that make them feel heard.
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Conversational Agent
Natural interactions with humans that make them feel heard.
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Conversational Agent
Natural interactions with humans that make them feel heard.
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Customer Support
Resolves issues, answers questions, and holds the line without losing the human touch.
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Customer Support
Resolves issues, answers questions, and holds the line without losing the human touch.
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Customer Support
Resolves issues, answers questions, and holds the line without losing the human touch.
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Concierge
Schedules, reschedules, and confirms without making the customer feel like they're fighting a system.
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Concierge
Schedules, reschedules, and confirms without making the customer feel like they're fighting a system.
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Narration
Podcasts, audiobooks, explainer videos, news briefings, and documentary narration. Studio quality without the studio.
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Narration
Podcasts, audiobooks, explainer videos, news briefings, and documentary narration. Studio quality without the studio.
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Video Voiceover
Sounds like it belongs in the story, in any language.
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Video Voiceover
Sounds like it belongs in the story, in any language.
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Video Voiceover
Sounds like it belongs in the story, in any language.
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Accessibility
Clear, natural narration for every interface built around the listener
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Accessibility
Clear, natural narration for every interface built around the listener
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Accessibility
Clear, natural narration for every interface built around the listener
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Your first voice agent in just 5 lines of code
Your first voice agent in just 5 lines of code
WebSocket · SSE · HTTP streaming or batch, your choice.
WebSocket · SSE · HTTP streaming or batch, your choice.
What makes our
Lightning v3.1 model different
Built for teams that ship voice products
not teams that experiment with them.
Built for teams that ship voice products not teams that
experiment with them.
Broadcast-Quality Audio
44.1 kHz native sample rate. WVMOS score of 5.06 the highest in the Lightning family. sounds like it was recorded in a studio, not synthesized by a machine.
Real-Time, Every Time
<100ms latency at 20 concurrent requests. RTF of 0.3 audio generates 3.3× faster than playback speed. Built for live voice agents, not batch exports.
Voice Cloning
Clone any voice in 5 to 15 seconds. No limits on how many. Use yours, build a new one, or start with one you love. Ready to deploy at any scale.
15 Languages
English, Spanish, Hindi, French, German, Italian, Portuguese, Swedish, Dutch, Tamil, Telugu, Malayalam, Kannada, Marathi, and Gujarati.
Lightning v3.1 makes a leap in voice quality
Lightning v3.1 makes
a leap in voice quality
Same text. Two models. Press play on both
the gap is immediately audible.
Same text. Two models. Press play on both the gap is immediately audible.
PREVIOUS VERSION
Lightning v2
Lightning v2
24 kHz · Previous generation
ALL NEW
Lightning v3.1
Lightning v3.1
44.1 kHz · Broadcast quality
Common questions about Lightning TTS
How many languages does Lightning V3.1 support?
Lightning V3.1 supports 15 languages, with more being added regularly. Best in class languages include English, Spanish, Hindi and Tamil. We have a strong coverage across Europe with French, German, Italian, Portuguese, Swedish, and Dutch, along with Indic support with Hindi, Tamil, Telugu, Malayalam, Kannada, Marathi, and Gujarati. If your language isn't on the list yet, it likely will be soon.
How many languages does Lightning V3.1 support?
Lightning V3.1 supports 15 languages, with more being added regularly. Best in class languages include English, Spanish, Hindi and Tamil. We have a strong coverage across Europe with French, German, Italian, Portuguese, Swedish, and Dutch, along with Indic support with Hindi, Tamil, Telugu, Malayalam, Kannada, Marathi, and Gujarati. If your language isn't on the list yet, it likely will be soon.
How long does voice cloning take and how much audio do I need?
Under 15 seconds of audio is all it takes. The clone is ready instantly and built to deploy at any scale from day one.
How long does voice cloning take and how much audio do I need?
Under 15 seconds of audio is all it takes. The clone is ready instantly and built to deploy at any scale from day one.
What is the latency and can I use it for real-time applications?
Lightning V3.1 delivers under 100ms time-to-first-audio. It was built specifically for real-time applications, so low latency isn't a trade-off you make. It's the default.
What is the latency and can I use it for real-time applications?
Lightning V3.1 delivers under 100ms time-to-first-audio. It was built specifically for real-time applications, so low latency isn't a trade-off you make. It's the default.
How is usage billed and is there a free tier?
You get $10 in free credits when you sign up, no strings attached. After that it's pay-as-you-go, so you only pay for what you use. For teams that need massive scale or high concurrency, we offer custom enterprise plans. Reach out to sales and we'll build something that works for you.
How is usage billed and is there a free tier?
You get $10 in free credits when you sign up, no strings attached. After that it's pay-as-you-go, so you only pay for what you use. For teams that need massive scale or high concurrency, we offer custom enterprise plans. Reach out to sales and we'll build something that works for you.
What industries and use cases is Lightning built for?
Lightning powers voice agents, IVR systems, audiobook generation, podcast production, gaming dialogue, accessibility tools, and any application where the voice is the product. Our enterprise customers span fintech (payment IVR), healthcare (appointment reminders, clinical agents), insurance (claims processing), travel (booking and support), telecom (digital-first support), and AI voice agent platforms that use Lightning as their TTS layer.
What industries and use cases is Lightning built for?
Lightning powers voice agents, IVR systems, audiobook generation, podcast production, gaming dialogue, accessibility tools, and any application where the voice is the product. Our enterprise customers span fintech (payment IVR), healthcare (appointment reminders, clinical agents), insurance (claims processing), travel (booking and support), telecom (digital-first support), and AI voice agent platforms that use Lightning as their TTS layer.
What audio formats does the API output?
Lightning V3.1 supports PCM, MP3, WAV, and mulaw.
What audio formats does the API output?
Lightning V3.1 supports PCM, MP3, WAV, and mulaw.
Is my data stored or used to train your models?
No, your data is yours. We log interactions for operational purposes only and never use your data to train our models. What you build with Lightning stays between you and your users.
Is my data stored or used to train your models?
No, your data is yours. We log interactions for operational purposes only and never use your data to train our models. What you build with Lightning stays between you and your users.
Can I control emotion, pace, and expressiveness?
Lightning V3.1 voices are designed to be naturally expressive and adapt to the context of what's being said without you having to dial anything in. For teams that want more direct control, V3.2, our instructional model, is coming soon. Stay tuned.
Can I control emotion, pace, and expressiveness?
Lightning V3.1 voices are designed to be naturally expressive and adapt to the context of what's being said without you having to dial anything in. For teams that want more direct control, V3.2, our instructional model, is coming soon. Stay tuned.
What support and SLAs are available for enterprise customers?
Smallest.ai runs at 99.99% uptime for enterprise clients, is SOC 2 aligned, HIPAA compliant, GDPR compliant, and ISO aligned. For dedicated support, SLAs, and on-premise deployment options, reach out to our sales team and we'll set up the right plan for your needs.
What support and SLAs are available for enterprise customers?
Smallest.ai runs at 99.99% uptime for enterprise clients, is SOC 2 aligned, HIPAA compliant, GDPR compliant, and ISO aligned. For dedicated support, SLAs, and on-premise deployment options, reach out to our sales team and we'll set up the right plan for your needs.
Your data, secure with Enterprise Security
Your data is secured by top SOC 2 Type 2, HIPAA, and PCI compliance standards, both in the cloud and on-premises.
We comply with HIPAA to protect your health information.
Smallest.ai has undergone SOC 2 Type II attestation and undergoes annual audits.
Strict internal audit processes for data management.
Infrastructure that meets ISO standards
Your data, secure with Enterprise Security
Your data is secured by top SOC 2 Type 2, HIPAA, and PCI compliance standards, both in the cloud and on-premises.
We comply with HIPAA to protect your health information.
Smallest.ai has undergone SOC 2 Type II attestation and undergoes annual audits.
Strict internal audit processes for data management.
Infrastructure that meets ISO standards
Your data, secure with Enterprise Security
Your data is secured by top SOC 2 Type 2, HIPAA, and PCI compliance standards, both in the cloud and on-premises.
We comply with HIPAA to protect your health information.
Smallest.ai has undergone SOC 2 Type II attestation and undergoes annual audits.
Strict internal audit processes for data management.
Infrastructure that meets ISO standards
The last TTS
model you'll need
Instant access
Instant access
$10 free credits
$10 free credits
SOC 2 Compliant
SOC 2 Compliant