Smallest.ai
Smallest.ai is a developer-first voice AI platform with TTS, STT, speech-to-speech models, telephony and hosting on one API-first bill.
If you are building a phone or realtime voice agent and want STT, TTS, speech-to-speech, telephony and hosting under one API, Smallest.ai is one of the few stacks that covers the whole loop, and its HIPAA zero-data-retention add-on plus on-prem Enterprise path are the reasons regulated teams look here instead of at a pure TTS vendor. The per-minute math is the catch: hosting at $0.01/min plus STT at roughly $0.009/min plus an LLM plus TTS at roughly $0.09/min stacks, and the quoted $0.09-$0.21/min agent range is a starting point, not a bill. Prototype on the $10 credit, then model your real traffic. If you need only one modality, ElevenLabs or Deepgram have deeper single-modality tooling.
Verified 3d ago · liveness 77/100 · cite: rightaichoice.com/tools/smallest-ai
- Engineering teams building realtime voice agents on an API-first stack
- Healthcare, finance and telecom buyers who need HIPAA, SOC 2 or on-prem deployment
- Teams that want STT, TTS, speech-to-speech, telephony and hosting on one bill
- Developers comparing cascading pipelines against native speech-to-speech
- Non-developers looking for a drag-and-drop, no-code voice bot builder
- Teams that need only one modality, where a dedicated TTS or STT vendor fits better
- High-volume deployments whose unit economics break once hosting, STT, TTS and LLM costs stack
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Skip Smallest.ai if you need only one piece of the stack, since a dedicated STT or TTS vendor will be cheaper, or if you have no engineering capacity to call APIs and wire up telephony yourself.
Hosting is billed separately at a flat $0.01/min on top of every model layer, so your effective per-minute cost is always higher than the TTS or STT rate alone.
Pay-as-you-go suits solo builders, pilots and small deployments: $10 in free credits, no commitment, $0.01/min hosting, roughly $0.009/min STT and roughly $0.09/min TTS, with agents landing at $0.09-$0.21/min. That undercuts enterprise-focused voice stacks that require contracts up front, but it is meaningfully more expensive per minute than using a single-modality TTS or STT vendor when you only need one layer. Regulated teams needing SSO, on-prem, 99.99% SLAs or HIPAA zero-retention move to
In short
Smallest.ai — Smallest.ai is a developer-first voice AI platform with TTS, STT, speech-to-speech models, telephony and hosting on one API-first bill. Best for Engineering teams building realtime voice agents on an API-first stack, Healthcare, finance and telecom buyers who need HIPAA, SOC 2 or on-prem deployment, Teams that want STT, TTS, speech-to-speech, telephony and hosting on one bill. Free to use.
What's new in Smallest.ai
Checked 3 days agoAcross the latest 5 updates: 5 news mentions.
Smallest.ai guide on choosing a speech-to-text API for low-resource languages
Smallest.ai published guidance on selecting speech-to-text APIs for low-resource languages, relevant if your agent needs coverage beyond the major languages.
Smallest.ai publishes streaming TTS guide for Node.js
A technical guide on streaming TTS in Node.js covering transport, codec and buffering choices when wiring Lightning into a realtime agent.
Smallest.ai on network jitter and packet loss in AI voice agents
An explainer on how network jitter and packet loss degrade AI voice agent quality, useful context for teams shipping phone agents.
Pocket reached $100M ARR in 7 months on Smallest.ai Pulse STT
A case study stating that Pocket reached $100M ARR in seven months using the Pulse STT model, cited as a production-reliability signal.
Smallest.ai announces Series A funding
Smallest.ai announced a Series A funding round; terms and investors were not disclosed in the post.
What people actually say about Smallest.ai — is it worth it?
We ran a structured research pass across product reviews, community discussions, and post-purchase forum threads to surface the patterns vendors won't publish themselves. Below: the recurring strengths, the hidden costs people mention most, and the cohort that consistently regrets adopting this tool.
45 mentions across 3 sources (Hacker News, YouTube, Product Hunt) · researched Aug 19, 2026.
Average across the 3 sources that answered — each source counts once, not each post.
- +Lightning TTS delivers sub-120ms latency, praised on Hacker News.
- +Supports 15+ languages and 38 STT languages, broad reach.
- +Free $10 credits let developers prototype without cost.
- +Native speech-to-speech model (Hydra) is a differentiator.
- +SOC 2, GDPR, HIPAA compliance suits regulated industries.
- −Limited community feedback makes it hard to gauge reliability.
- −Product Hunt UI critique suggests website design needs polish.
- −No public cost breakdown for enterprise plans.
- −Voice cloning quality not fully validated by user reviews.
- −Documentation and tutorials are sparse for new users.
- • Potential costs for on-premise deployment and dedicated infrastructure are not public.
Viability Score
How well maintained and how widely used is Smallest.ai? Built from what the vendor actually publishes (docs, changelog, tutorials, integrations, pricing), whether the site is live, and how much real users discuss it. How we calculate this
Last calculated: October 2026
How we score →Key Features
- Lightning V3.1 Pro text-to-speech with sub-100ms latency (15+ languages on the model card, 70+ quoted on the homepage)
- Pulse realtime speech-to-text across 38+ languages with 64ms latency
- Pulse emotion and speaker detection in transcription output
- Hydra full-duplex speech-to-speech model (Beta) that listens, reasons and responds in real time
- Electron sub-3B small language model the site compares against GPT-4.1
- Cascading STT + LLM + TTS pipelines or end-to-end speech-to-speech, same agent
- Real-time streaming speech-to-text API
- Agents Playground for configuring voice, languages and agent behaviour in one interface
- Voice cloning
- Telephony: rent a number at $10/number/month or bring your own telephony at cost
- On-premise deployment on the Enterprise plan
- Knowledge base add-on ($3/GB/user, $2 per 1K queries)
- PII removal add-on at $0.01/min
- Post-call analytics (10 per agent included on pay-as-you-go)
- Web widget for embedding voice agents on a site
About Smallest.ai
Smallest.ai is a voice AI platform built on the thesis that many specialised small models beat one giant one. Its production audio models are Lightning V3.1 Pro text-to-speech (sub-100ms latency, 15+ languages on the model page, 70+ languages quoted on the homepage), Pulse speech-to-text across 38+ languages with 64ms latency plus emotion and speaker detection, Hydra, a full-duplex speech-to-speech model marked Beta, and Electron, a sub-3B language model. You can build a cascading pipeline (hosting + STT + LLM + TTS + telephony) or run end-to-end speech-to-speech, and the Agents Playground lets you configure voice, languages and behaviour in one interface. Everything is API-first: pay-as-you-go starts with $10 in free credits, hosting is a flat $0.01/min, agents run $0.09-$0.21/min depending on architecture, STT is roughly $0.009/min and TTS roughly $0.09/min, and rented phone numbers cost $10/number/month. Knowledge Base ($3/GB/user, $2 per 1K queries), PII removal ($0.01/min), and HIPAA zero-data-retention ($1,000/mo) are add-ons rather than bundled. The platform is SOC 2, GDPR and HIPAA compliant, and on-premise deployment, SSO, 99.99% SLAs and advanced campaigns sit on the Enterprise plan. It is aimed at engineering teams shipping phone and realtime voice agents, and at regulated buyers who need a self-hosting or zero-retention path, rather than at no-code builders.
Behind the Verdict
Smallest.ai's pitch is narrow and honest: small specialised audio models, an API-first runtime, and a self-hosting path, sold to engineers rather than marketers. What you actually get is four models, Lightning V3.1 Pro for text-to-speech, Pulse for speech-to-text, Hydra for full-duplex speech-to-speech, and Electron, a sub-3B language model the site says outperforms GPT-4.1. The homepage quotes Lightning at sub-100ms latency across 70+ languages while the model card says 100ms across 15+ languages; that inconsistency sits in the vendor's own copy, so verify the language list against the model docs before you commit. Pulse is the safest of the four to plan around, at 38+ languages and 64ms latency, and the Pocket case study claims $100M ARR in seven months on Pulse STT, which is the kind of production-reliability signal teams ask about. The real strength is the whole loop. Cascading (hosting + STT + LLM + TTS + telephony) and speech-to-speech (hosting + S2S + telephony) are both supported, so you are not gluing three vendors together, and you can compare architectures against the same agent in the Playground. Compliance is unusually complete for a company this size: SOC 2 Type 2, ISO 27001, GDPR and HIPAA, with on-premise deployment, SSO, advanced denoising and 99.99% uptime SLAs on Enterprise, plus a HIPAA zero-data-retention add-on at $1,000/mo. The weakness is the bill. Hosting is a flat $0.01/min, but STT (~$0.009/min), TTS (~$0.09/min), the external LLM layer at cost, and telephony all stack on top, so the headline $0.09-$0.21/min agent range is an estimate that depends entirely on your architecture. Speech-to-speech is cheaper per minute than a naive cascade but Hydra is still marked Beta. Several things you may want are gated: advanced campaigns and text messaging are listed as coming soon on pay-as-you-go, post-call analytics are capped at 10 per agent, custom branding and custom integrations are Enterprise-only, and concurrency is capped at 20 included minutes before you negotiate more. A single-modality buyer is overpaying for a bundle they will not use, and any high-volume deployment should model per-minute cost at real traffic before signing anything. Where it fits: engineering teams shipping multilingual support lines, outbound qualification, IVR, receptionists or dubbing, especially in healthcare, finance or telecom where an on-prem or zero-retention path matters. Where it does not: non-developers who want a drag-and-drop voice bot builder, single-modality buyers who should be with ElevenLabs or Deepgram, and anyone whose unit economics break above roughly ten cents a minute.
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Real-world workflow fit
Concrete scenarios for the personas Smallest.ai actually fits — and what changes day-one when you adopt it.
You sign up, spend part of the $10 credit, call the Lightning V3.1 Pro TTS endpoint alongside Pulse STT to build a cascading agent, then configure voice and languages in the Agents Playground before wiring telephony.
Outcome: A working phone agent on pay-as-you-go with 20 included concurrency and unlimited agents, billed per minute with no contract.
You pilot on pay-as-you-go, then move to Enterprise to get SSO, on-premise deployment, a 99.99% uptime SLA and the $1,000/mo HIPAA zero-data-retention add-on before patient data touches the system.
Outcome: A compliance-approved deployment where call audio is not retained and the runtime sits inside your own infrastructure.
You build the same agent twice in the Playground, once as hosting + STT + LLM + TTS + telephony and once as hosting + Hydra speech-to-speech + telephony, and measure latency and cost on real traffic.
Outcome: A concrete per-minute comparison, since speech-to-speech bills at model cost plus hosting while the cascade adds an STT layer at roughly $0.009/min and TTS at roughly $0.09/min.
Use Cases
- Build multilingual voice agents for customer support that hold realtime phone conversations.
- Run outbound sales qualification or collections calls with a voice agent at $0.09-$0.21/min depending on architecture.
- Deploy white-label AI receptionists for agencies offering branded phone answering.
- Add realtime voice interaction to a web app using the Web Widget.
- Transcribe meetings, interviews or calls with Pulse STT and speaker detection.
- Integrate realtime transcription and voice response into IVR call routing.
- Generate voiceovers for podcasts, media and product demos with Lightning TTS.
- Dub video into multiple languages with AI voice generation.
Models Under the Hood
as of 2026-10-02
Limitations
- Pricing is usage-based and layered: hosting is a flat $0.01/min, with STT around $0.009/min, TTS around $0.09/min, an external LLM layer billed at cost, and telephony on top, so agent calls land at roughly $0.09-$0.21/min depending on whether you cascade or run speech-to-speech.
- Concurrency is capped at 20 included on pay-as-you-go, with additional concurrency requiring a custom plan.
- Several capabilities are listed as coming soon or Enterprise-only: advanced campaigns and text messaging on pay-as-you-go, custom integrations, advanced denoising, custom branding, priority support, prompt engineering support, extra agent concurrency, on-premise deployment and SSO.
- Post-call analytics are limited to 10 per agent unless you are on Enterprise.
- Hydra, the speech-to-speech model, is marked Beta.
- The vendor's own copy is inconsistent on Lightning TTS language coverage (70+ on the homepage vs 15+ on the model card), so confirm the supported language list before committing.
as of 2026-10-04
Verification history
We have re-verified Smallest.ai 9 times since . Each pass re-reads the vendor's own pages and re-checks every listed field against that evidence; passes where nothing had changed are marked as such.
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
Showing the 6 most recent of 9 verification passes.
Free to cite with attribution — this page re-verifies continuously.
12-month cost
Project the real annual outlay, including the implied monthly cost when only an annual tier is published.
Vendor list price only. Add-on usage, seat overages, and contract minimums are surfaced under Hidden costs & gotchas.
Plans compared
For each published Smallest.ai tier: who it actually fits, and what it adds vs. the previous tier. Cross-reference the cost calculator above for projected annual outlay.
Pay As You Go
$0/mo (start with $10 in free credits)
Ideal for
Solo builders, prototyping teams and small-scale deployments that want full API access with no contract and a $10 credit to start
What this tier adds
Free entry point: full API and model access, $0.01/min hosting, 20 included concurrency, unlimited agents, add-ons billed separately
Enterprise
Custom
Ideal for
Healthcare, finance, telecom and other regulated teams running production voice traffic who need SLAs, SSO, on-prem or zero-retention
What this tier adds
Adds dedicated infrastructure, 99.99% uptime SLA, SSO, on-premise deployment, extra concurrency, advanced denoising, custom integrations and priority support over pay-as-you-go
Where the pricing makes sense
The company stage and team size where Smallest.ai's pricing actually pencils out — and where peers do it cheaper.
Pay-as-you-go suits solo builders, pilots and small deployments: $10 in free credits, no commitment, $0.01/min hosting, roughly $0.009/min STT and roughly $0.09/min TTS, with agents landing at $0.09-$0.21/min. That undercuts enterprise-focused voice stacks that require contracts up front, but it is meaningfully more expensive per minute than using a single-modality TTS or STT vendor when you only need one layer. Regulated teams needing SSO, on-prem, 99.99% SLAs or HIPAA zero-retention move to
Setup time & first value
How long it actually takes to get something useful out of Smallest.ai — broken out by persona, not the marketing-page minute.
Backend engineers can make a first TTS or STT API call within minutes of signing up, since access is immediate on the $10 free credit and no sales call is required. A working phone agent takes longer, because you still need to pick an architecture, configure the Playground, rent a number at $10/number/month or connect your own telephony, and test latency. Regulated buyers should budget weeks, not
Switching to or from Smallest.ai
How to bring data in from common predecessors and how to get it back out — written for the switcher, not the buyer.
- →From ElevenLabs: keep your voice assets, move TTS calls to the Lightning V3.1 Pro endpoint and add Pulse STT plus telephony so the whole loop bills on one invoice.
- →From Deepgram: point your existing realtime STT streaming calls at Pulse, then add a TTS layer from the same account instead of running two vendors.
- →From a DIY cascade of separate vendors: replace the STT and TTS hops with Pulse and Lightning, keep your own LLM, and let Smallest host the runtime at $0.01/min.
- →From Vapi or LiveKit: keep your orchestration layer and swap the underlying model endpoints to Smallest's STT, TTS and speech-to-speech APIs.
- ↗To ElevenLabs: if you only need text-to-speech, move your Lightning calls to a dedicated TTS vendor and drop the hosting and telephony layers.
- ↗To Deepgram: if you only need transcription, replace Pulse with a single-modality STT vendor and stop paying the $0.01/min hosting fee.
- ↗To a no-code voice bot builder: if your team cannot maintain API integrations, export your prompts and scripts and rebuild the agent on a visual canvas.
- ↗To self-hosted open models: if the per-minute stack outstrips your budget, take the open-weight audio models in-house and operate the runtime yourself.
Integrations
Resources & Guides
Tutorials & Learning
Building World's Fastest Text-to-Speech Model: Lessons from Smallest.ai
SeedToScale
Smallest.aiでビジネス向け音声AIツールを構築する方法 | 最高の音声AI
Jon Law
Turn Text To Human-Like Speech FAST With Smallest.ai
AI Demos
YouTube returned 6 videos for “Smallest.ai”, and we withheld 3: 3 could not be judged, because “Smallest.ai” is a single word that other videos use for other things. Showing the 3 we can prove are about Smallest.ai.
Official links
Tools that pair well with Smallest.ai
Common stack mates teams adopt alongside Smallest.ai, with the specific reason each pairing earns its keep.
Fish Audio
Fish Audio turns text into expressive, emotionally controllable speech with voice cloning from 15 seconds of audio and a free developer TTS API.
ElevenLabs
ElevenLabs turns text into ultra-realistic AI voice, music, dubbing and conversational voice agents from one credit pool.
Converse Now
Voice AI that answers restaurant phone and drive-thru orders with a customizable, branded persona.
Featured Head-to-Head Comparisons
Smallest Ai vs Locus Robotics
If you run a busy warehouse and need to 2–3x picking productivity with real-time orchestration, choose Locus Robotics. If you're building voice-based AI assistants or conversational IVR with ultra-low latency, Smallest.ai is the clear pick. These tools solve completely different problems—pick based on your domain.
Smallest Ai vs Presto Voice
If you're a QSR chain aiming to boost drive-thru revenue with automated upselling, Presto Voice is purpose-built and proven (Dairy Queen just adopted it). For developers needing ultra-low-latency voice models and flexible API integration across industries, Smallest.ai offers unmatched performance and compliance. Choose based on your domain: restaurant operations vs. general-purpose voice AI.
Smallest Ai vs Truleo
Truleo and Smallest.ai serve entirely different markets—law enforcement intelligence vs. real-time voice AI development. Your choice depends solely on domain: if you're a police department drowning in siloed data, Truleo is your only option; if you're building voice agents for customer support or collections, Smallest.ai's sub-100ms TTS and #1 STT are unmatched. There is no overlap in buyer personas.
Alternatives to Smallest.ai
View all
Fish Audio
Fish Audio turns text into expressive, emotionally controllable speech with voice cloning from 15 seconds of audio and a free developer TTS API.
ElevenLabs
ElevenLabs turns text into ultra-realistic AI voice, music, dubbing and conversational voice agents from one credit pool.
Converse Now
Voice AI that answers restaurant phone and drive-thru orders with a customizable, branded persona.
Frequently Asked Questions
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