Smallest.ai
by Smallest.ai
Sub-second voice AI — small, specialised speech models for real-time enterprise voice agents
Smallest.ai builds small, specialised speech models — text-to-speech, speech-to-text, speech-to-speech and a compact language model — plus a platform for deploying real-time voice agents. It targets enterprises in regulated sectors such as financial services, healthcare and contact centres that need interruptible, low-latency phone conversations rather than narration or dubbing, and it competes on speed and cost per minute rather than expressive range.
Smallest.ai is a voice AI company built on the thesis that real-time conversation needs many small specialised models rather than one large general-purpose one. Its stack is four models plus a deployment platform: Lightning, a text-to-speech model quoting sub-100ms time-to-first-audio across 15 or more languages at 44.1kHz; Pulse, speech-to-text covering 38 languages with speaker and emotion detection; Electron, a roughly four-billion-parameter small language model that handles the real-time conversational turn and hands off to a larger offline LLM only when a query exceeds its knowledge; and Hydra, a native speech-to-speech model whose asynchronous architecture runs listening, reasoning, acting and responding in parallel to cut the dead air that makes an interruptible phone call feel wrong. These sit behind Atoms, a dashboard, playground and API for configuring voices, languages and agent behaviour and deploying to rented phone numbers or a web widget. Founded in 2023 by Sudarshan Kamath and Akshat Mandloi, the company employs roughly 60 people and closed a $13 million Series A on 30 July 2026 led by Seligman Ventures with Sierra Ventures and 3one4 Capital participating, taking total funding past $21 million within about nine months of an $8 million seed. It launched Voice 4.0 alongside the round and reports a 76% naturalness win rate against OpenAI's gpt-4o-mini-tts, a 5.38% word error rate and a 3.89 mean opinion score. RingCentral and Truecaller are named customers. The company sells into financial services, healthcare and contact centres with SOC 2 Type 2, ISO 27001, GDPR, HIPAA and PCI compliance plus on-premise and private-cloud deployment, and frames its edge as hardware-level: roughly 550 simultaneous voice calls on about $27,000 of P100 accelerators against around $100,000 of NVIDIA L40S GPUs.
A contact-centre or CX engineering lead in a regulated industry who needs voice agents that can be interrupted mid-sentence and still cost cents per minute at production volume.
Sub-second, interruptible voice conversations at roughly $0.09 to $0.21 per minute, deployable on-premise where the audio is not allowed to leave the network.
At a Glance
- Category
- Audio & Voice
- Pricing
- Usage-based, Freemium, Contact for pricing
- Target Market
- CTOs, VP Customer Experience, Contact Centre Leaders, Enterprise Developers, Product Engineers
- Deployment
- Cloud-first, API-based, Self-hosted, Hybrid
- Founded
- 2023
- Team Size
- 51-200
Key Features
- ✓Lightning text-to-speech
Sub-100ms time-to-first-audio at 44.1kHz across 15 or more languages, with prosody tuned for conversational turn-taking rather than narration.
- ✓Hydra speech-to-speech
Asynchronous architecture that listens, reasons, acts and responds in parallel, cutting the lag that makes interruptions feel unnatural on a call.
- ✓Pulse speech-to-text
Transcription across 38 languages with speaker and emotion detection, so an agent can react to tone as well as to words.
- ✓Electron small language model
A roughly four-billion-parameter model handling the real-time turn, escalating to a larger offline LLM only for genuinely complex queries.
- ✓Atoms agent platform
Dashboard, playground and API for configuring voices, languages and behaviour, then deploying to phone numbers or a web widget.
- ✓Fast voice cloning
Production voice cloning from as little as five seconds of reference audio, avoiding the studio recording sessions rivals require.
- ✓On-premise and private-cloud deployment
The full model stack runs inside the customer's own environment, which is what makes regulated healthcare and banking deployments possible at all.
Capabilities
Use Cases
- •Contact-centre call deflection
A bank routes routine balance and payment queries to a voice agent that callers can interrupt without the conversation falling apart.
- •Outbound appointment and collections calling
Healthcare or lending teams run high-volume outbound campaigns where per-minute model cost decides whether the unit economics work.
- •Multilingual customer support
A support line handles callers who code-switch mid-sentence, with the agent following the language change rather than losing the thread.
- •Embedding speech into an existing product
A software vendor adds voice input and output to its own application through the API without building a speech stack in-house.
- •On-premise voice for regulated data
A hospital deploys the models inside its own infrastructure so patient audio never crosses the network boundary to a third party.
Ideal For
Best For
- ✓Real-time inbound and outbound phone agents in contact centres where response lag breaks the conversation
- ✓Regulated deployments in healthcare and financial services needing HIPAA and PCI compliance with on-premise or private-cloud hosting
- ✓High-volume voice workloads where per-minute cost rather than expressive range is the binding constraint
- ✓Multilingual voice agents needing mid-sentence language switching across 15 languages
- ✓Product teams embedding text-to-speech or speech-to-text into an existing application via API rather than buying a whole agent platform
Not Ideal For
- ✗Audiobook, narration, dubbing and podcast production — a competitor's head-to-head comparison describes the voices as lacking depth and emotional range, and professional voice cloning is not supported
- ✗Buyers who want the largest voice library and deepest customisation, since the same comparison rates the feature set as more limited and pronunciation context weaker than ElevenLabs
- ✗Teams optimising for the lowest published latency alone, where Cartesia quotes roughly 40 to 90ms against Smallest's sub-100ms plus network time
Integrations
Deployment
Market Analysis
Pros
- ✓Genuinely fast, with sub-100ms time-to-first-audio and an architecture built around interruption, which is the failure mode that makes most voice agents unusable on a phone call
- ✓Per-minute pricing of $0.09 to $0.21 is low enough that high-volume calling economics work, and the component breakdown is published rather than buried
- ✓Unusually complete compliance for a company founded in 2023 — SOC 2 Type 2, ISO 27001, HIPAA, PCI and GDPR — with on-premise deployment available
- ✓Named production customers in RingCentral and Truecaller, plus published benchmark figures (76% naturalness win rate over gpt-4o-mini-tts, 5.38% word error rate, 3.89 mean opinion score) rather than vague marketing claims
- ✓Deliberately narrow scope: it does one thing, real-time conversational voice, instead of spreading across dubbing and content generation
Cons
- ✗A competitor's head-to-head comparison rates the voices as lacking depth and emotional range, with less contextual awareness in pronunciation than ElevenLabs
- ✗Professional voice cloning is not supported and customisation options are characterised as basic relative to the market leader
- ✗The latency claims are model-only figures measured under favourable conditions and exclude network time, and Cartesia quotes lower numbers for its own model
- ✗Independent practitioner coverage is thin — no G2, Capterra or substantive Hacker News discussion surfaced, so there is very little unfiltered production experience to read before buying
- ✗Self-serve concurrency is capped at 20 simultaneous calls, so any real contact-centre deployment is an Enterprise negotiation with unpublished pricing
Pricing
Pay As You Go
From $0.09/minute
- ✓$10 in free credits to start
- ✓Unlimited agents
- ✓Full API suite access
- ✓20 concurrent calls
- ✓Web widget
- ✓Basic testing suite
- ✓Post-call analytics (10 per agent)
- ✓Email and community support
Enterprise
Contact for pricing
- ✓Dedicated infrastructure with 99.99% uptime SLA
- ✓On-premise deployment
- ✓SSO and advanced compliance (SOC 2, HIPAA)
- ✓Dedicated forward-deployed engineers
- ✓Priority and prompt-engineering support
- ✓Custom integrations and branding
Metered per minute of conversation rather than per seat: $0.09 to $0.21 all-in depending on model choice, and unusually the vendor publishes the component breakdown — roughly $0.009 per minute for speech-to-text, $0.09 for text-to-speech, $0.01 flat for hosting, plus whichever LLM you route to at $0.045 to $0.10 per minute. Phone numbers rent at $10 per month each and text messages cost $0.005. New accounts get $10 in free credits. Everything that makes it deployable inside a bank or hospital — on-premise hosting, SSO, the 99.99% SLA, dedicated infrastructure — is Enterprise-only and unpriced, and the self-serve tier caps concurrency at 20 calls, so real contact-centre volume forces a sales conversation.
Security & Compliance
Connect
Sources
This page was written from 5 sources, 3 on domains other than smallest.ai.
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