SimulSpeak
Real-time translated calls in 24 languages · they hear their language, in your voice.
SimulSpeak translates live calls as you speak: you talk in your language, the other side hears theirs, in your cloned voice, with sub-second latency. On the web, via a room link, over a normal phone call, or on one phone in person - the other side installs nothing.
ListenSimulSpeak. Real-time translated calls in 24 languages.
SimulSpeak translates live calls as you speak: you talk in your language, the other side hears theirs, in your cloned voice, with sub-second latency. On the web, via a room link, over a normal phone call, or on one phone in person - the other side installs nothing.
SimulSpeak shipped on time, with the brand and the engineering quality matching what we asked for. Iteration was tight · we kept the cadence weekly and the team responded same-day on production questions.
What's on screen
Frame breakdown
- 01User surface
The whole experience the user sees
This frame shows the live product: real-time translated calls in 24 languages · they hear their language, in your voice. Every component is ours · scope, design, code, deploy.
- 02Stack behind the screen
What's powering it: Next.js, TypeScript, WebRTC
5 stack components run behind this frame · Next.js, TypeScript, WebRTC drive the visible UI; the rest sit in the data layer. All studio-owned.
- 03What we shipped
Live voice translation in 24 languages
Talk to anyone without sharing a language
- 04Status
Live · simulspeak.com.
This isn't a demo · real traffic flows through it, with monitoring + weekly fixes attached.
How it shipped
Timeline- 01 · BRIEF
Scoped on a 30-min call.
Language barriers stall deals and conversations
- 02 · ARCHITECTURE
Stack decisions before any code.
Decision doc captured the data flow, Next.js, TypeScript, WebRTC, Voice AI role split, and the failure modes we'd handle in v1 vs defer. Cross-service boundaries (where AI ends and the web app begins) were drawn here so neither side leaked into the other later.
- 02 · BUILD
Engineering in our studio, no offshore.
Live voice translation in 24 languages
- 04 · POLISH
Performance, accessibility, and observability.
PSI / a11y / coverage budgets enforced as launch gates. Logging + metrics wired before cut-over · the team can answer 'is it working?' from a dashboard, not a Slack thread. Threat-model checklist signed off before traffic hits the box.
- 03 · SHIP
Live, observable, handed back.
Talk to anyone without sharing a language
What shipped
04- 01Build
Live voice translation in 24 languages
Talk to anyone without sharing a language
- 02Stack
Cloned voice · sounds like you
You speak every language in your own voice
- 03UX
Sub-second latency
The other side just answers the phone
- 04Ops
Web, room link, phone call, in-person mode
SimulSpeak translates live calls as you speak: you talk in your language, the other side hears theirs, in your cloned voice, with sub-second latency. On the web, via a room link, over a normal phone call, or on one phone in person - the other side installs nothing.
THE PROBLEM
- −Language barriers stall deals and conversations
- −Interpreters are expensive; translator apps are clunky and robotic
- −A foreign customer won't install an app to take a call
WHAT THE CLIENT GOT
- Talk to anyone without sharing a language
- You speak every language in your own voice
- The other side just answers the phone
WHAT WE DELIVERED
- +Live voice translation in 24 languages
- +Cloned voice · sounds like you
- +Sub-second latency
- +Web, room link, phone call, in-person mode
STACK
- Next.js
- TypeScript
- WebRTC
- Voice AI
- Twilio
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// try it yourself
This work is live. Open it and try it for yourself.
- SimulSpeakGlobal
Talk to anyone, in any language.