Overview
Sesame is a voice-AI research company that went viral for Maya and Miles — two voice personas that hold a genuinely free-flowing spoken conversation. Unlike traditional text-to-speech, Sesame’s Conversational Speech Model (CSM) is built for full-duplex dialogue: it can be interrupted mid-sentence, picks up on your tone, and uses natural filler, breath, and micro-pauses that make the exchange feel present rather than robotic. The base CSM model is open-source on Hugging Face under Apache 2.0, so developers can self-host it. As of 2026 Sesame monetizes mainly through research partnerships and a planned voice-first wearable device, which means the web demo and open model are best understood as a preview of where conversational voice is heading.
Key Features
- Full-duplex conversational voice — interrupts and responds to tone in real time, no turn-taking latency.
- Maya & Miles personas — two distinct, persistent voice characters with natural pacing and emotional inflection.
- Open-weight CSM — the 1B-parameter Conversational Speech Model is free to download and self-host under Apache 2.0.
- Free browser demo — talk to Maya or Miles with no account required, the fastest way to feel the technology.
- Emotionally expressive, low-latency speech — 200–300 ms responses that cross much of the ‘uncanny valley’ of voice AI.
- Wearable roadmap — Sesame’s long-term bet is a voice-first companion device, with the demo serving as a preview of that engine.
Pricing
| Plan | Price | For |
|---|---|---|
| Web Demo (Maya/Miles) | $0 | Free, no account; full-duplex voice chat in the browser |
| Open-Source CSM | $0 | Self-host the Apache 2.0 model on your own GPU |
| Future Hardware | TBA | Voice-first wearable device, no public pricing as of 2026 |
Comparison
vs. ElevenLabs: ElevenLabs is the production-grade choice for studio TTS, voice cloning, and dubbing at scale, with clear per-credit pricing. Sesame wins on live conversational realism but lags on enterprise features and a turnkey API.
vs. Hume AI: Hume’s EVI is the closest rival in emotional intelligence and empathy detection. Sesame is often praised for smoother prosody and lower latency, while Hume offers a more mature commercial API.
vs. ChatGPT: ChatGPT’s Advanced Voice Mode brings reasoning and multimodal context, but reviewers consistently find Sesame’s dedicated speech model more natural and emotionally present for pure conversation.