Right now, somewhere on Twitch, a streamer in São Paulo is pulling off one of the most impressive speedruns the internet has ever seen. Their commentary is electric. Their chat is exploding. They have 8,000 concurrent viewers and every single one of them speaks Portuguese.

On the other side of the planet, an English-speaking audience of millions will never know this streamer exists. Not because the content isn't good enough. Not because the gameplay isn't there. But because of a single, invisible wall that has defined the boundaries of online entertainment since the first webcam went live: language.

Today, we're tearing that wall down.

StreamFluent is the world's first real-time AI voice dubbing and caption platform built specifically for live streamers. You stream once, in your native language. StreamFluent listens, transcribes, translates, and re-voices your stream — in up to 15+ languages — each delivered to its own channel on Twitch, YouTube, Kick, or any RTMP-compatible platform.

This isn't post-production dubbing. This isn't subtitles you add after a VOD is uploaded. This is happening live, in sub-second latency, while you're gaming, reacting, or chatting with your audience.

Let us explain how we got here, what we built, and why we believe this changes everything for creators.

The Problem: Language Is the Last Barrier in Live Streaming

The streaming industry has solved almost every other distribution problem. You can go live from your bedroom and reach viewers on every continent. Platforms have global CDNs that deliver video in milliseconds. Discovery algorithms surface content to new audiences around the clock. Payment systems let fans in Tokyo tip a creator in Toronto.

But language? Language is still a hard wall.

Consider the math. There are roughly 2.5 million active streamers on Twitch alone. The vast majority of them stream in a single language. English dominates the Western platforms, but the fastest-growing streaming communities are in Spanish, Portuguese, Japanese, Korean, and Hindi. These audiences are massive, engaged, and largely siloed from each other.

A Spanish-speaking streamer with incredible gameplay and a magnetic personality hits a ceiling the moment their potential viewer doesn't speak Spanish. The same is true in reverse — an English creator with a loyal community of 50,000 has essentially zero reach into the 500-million-strong Japanese-speaking internet.

This isn't a small problem. It's the single largest untapped growth lever in the entire creator economy. And until now, the solutions have been either nonexistent or laughably impractical:

Manual translation? You'd need a human interpreter on a voice call, live, for every stream, in every language. The cost alone is prohibitive. The latency makes it unwatchable.
Post-stream subtitles? Better than nothing for VODs, but they do nothing for live viewership — which is where the money, the community, and the momentum are.
Browser-based caption overlays? A handful of tools exist, but they only handle text captions, require complex OBS plugin setups, and don't solve the fundamental problem: your voice is still in one language.

The streaming world needed something entirely new. A system that could process speech, translate it, and synthesize a new voice — all in real time, all without the streamer changing their workflow.

That's what we built.

What We Built: Real-Time AI Dubbing for Live Streams

StreamFluent is a real-time AI pipeline that sits between your streaming encoder (OBS Studio, Streamlabs, or any RTMP-compatible software) and your destination platforms. Here's what happens when you go live:

You stream normally in your native language. Nothing about your setup changes except the RTMP destination URL in OBS.
StreamFluent ingests your stream via our RTMP relay servers. Your video passes through untouched — we never re-encode your video.
Our AI pipeline processes your audio in real time: speech recognition transcribes what you're saying, machine translation converts it into your target languages, and neural text-to-speech synthesizes a new voice track for each language.
Each translated stream is delivered to its own destination — a separate Twitch channel, YouTube stream, or Kick channel — complete with the dubbed audio track and optional burned-in captions.

The result: you stream once. Your audience watches in fifteen languages. Each version sounds natural, stays in sync, and arrives with sub-second latency.

Let's break down each piece.

Speech Recognition (STT)

The first stage of the pipeline is automatic speech recognition. StreamFluent's STT engine processes your audio in real time, converting speech to text with high accuracy even in noisy gaming environments. We've optimized specifically for the streaming use case — fast-talking commentary, background game audio, overlapping sounds, and the general chaos of a live broadcast.

Machine Translation

Once we have your transcript, our translation layer converts it into your configured target languages. We currently support 15 languages: Spanish, Japanese, Portuguese, French, German, Korean, Chinese (Mandarin), Italian, Russian, Arabic, Hindi, Turkish, Dutch, Polish, and Thai — with more on the way.

The translation engine is tuned for conversational, informal speech — the way streamers actually talk — not the stiff, formal output you'd get from a generic document translator.

Neural Text-to-Speech (TTS)

This is where the magic happens. StreamFluent doesn't just display translated text. It speaks it. Our TTS engine generates a natural-sounding voice in the target language, synthesized in real time.

On our Pro plan, you can create a custom voice model from just a 30-second audio sample. The system learns the characteristics of your voice — tone, cadence, energy — and applies them to the translated output. Your Spanish stream sounds like you speaking Spanish, not a generic robot.

On our Business plan, we're rolling out full voice replication with emotion preservation — the dubbed voice will carry your excitement, frustration, and humor across languages. (This feature is coming soon, and early testers have called it "uncanny.")

Video Passthrough

A critical design decision: we never re-encode your video. Your 1080p60 or 4K stream passes through our relay servers bit-for-bit. We only touch the audio track (and optionally burn in caption overlays). This means zero quality loss, minimal added latency, and no extra GPU cost on your end.

How It Works: Setup in Under 2 Minutes

We obsessed over making StreamFluent ridiculously easy to set up. There are no plugins to install, no virtual audio cables to configure, no browser sources to wrestle with. Here's the entire flow:

Step 1: Create Your Account

Sign up at streamfluent.ai with your email or connect directly with your Twitch, YouTube, or Google account. The free tier is available immediately — no credit card required.

Step 2: Set Up Your Voice

For Pro and Business users, record a 30-second voice sample directly in the dashboard. Our system uses this to build your custom voice profile. You can adjust speaking rate (0.5x to 2.0x) and pitch (-12 to +12 semitones) to fine-tune how your dubbed voice sounds.

Free tier users get access to our high-quality standard TTS voices — still natural-sounding, just not personalized to your specific voice.

Step 3: Add Your Destinations

This is where you configure where each language goes. For each target language, you specify:

The language (e.g., Spanish, Japanese)
The platform (Twitch, YouTube, Kick, or any custom RTMP URL)
The stream key for that channel
The dubbing mode: full AI dubbing, captions only, or both

You can run as many destinations as your plan allows — one on the Free tier, up to three on Pro, and unlimited on Business.

Step 4: Connect OBS and Go Live

Here's the part that surprises everyone: you just change your stream URL in OBS. That's it.

Go to OBS Studio → Settings → Stream → select "Custom..." → paste in your StreamFluent RTMP URL and stream key. These are generated automatically in your dashboard.

Server: rtmp://ingest.streamfluent.ai/live
Stream Key: (your unique key from the dashboard)

Hit "Start Streaming" in OBS. StreamFluent takes over from there. Your original stream goes to your main channel (if you've configured a passthrough destination), and each translated version goes to its respective platform channel.

No plugins. No virtual audio drivers. No browser sources. If your encoder can output RTMP — and virtually all of them can — it works with StreamFluent.

Captions and Dubbing: Full Control, Per Destination

One of the most requested features during our beta was granular control over captions and dubbing on a per-destination basis. Different audiences have different preferences, and we wanted to give streamers complete flexibility.

Here's how it works:

Dubbing Modes

Each destination can be set to one of three modes:

Auto Dub: If the destination language differs from your source language, full AI voice dubbing is applied. This is the default and the most common setting.
Captions Only: Your original voice is preserved, but translated captions are burned into the video. Great for audiences who prefer to hear the original voice but need translation assistance.
Original Only: The stream passes through with no dubbing and no captions. Useful for your "home" language destination.

Burned-In Captions

StreamFluent's caption system renders translated text directly into the video feed — no viewer-side extension or setting required. Everyone watching sees the captions, regardless of their device or platform.

You can customize:

Position: Bottom center or top center
Font size: 16px to 48px (default 24px)
Language: Captions match the destination language

Captions work independently of dubbing. You can run captions-only on some destinations and full dubbing on others. You can even run both — dubbed audio with matching captions — for maximum accessibility.

Audio Mixing

When dubbing is active, StreamFluent automatically handles audio mixing:

Original audio volume: Defaults to 20% (your original voice becomes a subtle background, preserving natural stream sounds)
Dubbed audio volume: Defaults to 100%
Auto-ducking: When the dubbed voice is speaking, the original audio is automatically lowered. When there's silence (gameplay audio only, no speech), the original audio comes back up.

All of these are adjustable per-stream from the dashboard.

Built for Reliability: What Happens When Things Go Wrong

Live streaming is unforgiving. If something breaks, there's no "undo." We built StreamFluent with this reality at the core of every architectural decision.

Latency Modes

Different use cases demand different latency-quality tradeoffs. StreamFluent offers three modes:

Ultra-Low Latency (< 500ms): For competitive gaming and fast-paced interaction. Available on the Business plan.
Balanced (< 1 second): The recommended default for most streamers. Available on Pro and Business.
Quality (< 2 seconds): Prioritizes translation accuracy over speed. Best for talk-heavy content.

Fallback Behavior

If the AI pipeline encounters an issue mid-stream — a brief network hiccup, a momentary processing delay — StreamFluent doesn't just crash or go silent. You configure what happens:

Pass Through (default): The original, untranslated audio is output until the pipeline recovers. Your audience hears you in your native language for a moment, then dubbing resumes seamlessly.
Mute: The dubbed audio track goes silent briefly. Useful if you'd rather have silence than untranslated audio.
Show Overlay: A brief on-screen message indicates that translation is temporarily unavailable.

Live Monitoring Dashboard

While you're live, the StreamFluent dashboard gives you a real-time command center:

Per-destination status: See if each language output is healthy, along with viewer counts and latency
Audio levels: Visual meters for each output stream
Live transcription feed: Watch the real-time transcript in every language, with tabs to switch between them
TTS preview: Listen to the dubbed audio directly in your browser to verify quality
Mid-stream controls: Enable or disable individual destinations without stopping your stream

The Vision: A World Where Every Streamer Has a Global Audience

We started StreamFluent because we believe language shouldn't determine a creator's ceiling.

The internet was supposed to be borderless. And in many ways, it is — you can watch a stream from anywhere in the world, instantaneously. But "watching" and "understanding" are two very different things. A viewer in Seoul might technically be able to load a Brazilian Twitch channel, but if they can't understand a word being said, they'll leave in seconds.

This creates an invisible segregation. The streaming world is fractured into language silos, and creators are trapped inside them. A brilliant entertainer in Mexico City will never organically reach the Japanese market. A Korean variety streamer with 100,000 loyal followers has no path to the English-speaking audience that's 10x larger.

StreamFluent is the bridge.

We envision a future where:

A streamer in Buenos Aires goes live and simultaneously entertains audiences in Tokyo, Berlin, Mumbai, and Los Angeles — all hearing the stream in their own language, in a voice that sounds like the creator's.
Language is no longer a variable in the discovery algorithm. Content quality is all that matters.
The creator middle class expands globally, because talent is evenly distributed across languages but opportunity no longer has to be.
Multilingual communities form around creators, with chat translation and cross-language interaction as a native feature (yes, we're working on that too).

This is a big vision. We're not there yet. But with today's launch, the foundation is in place.

Pricing: Start Free, Scale As You Grow

We designed StreamFluent's pricing to be accessible to creators at every level.

Free Plan — $0/month

30 caption minutes and 15 dubbed minutes per month
1 target language
Standard TTS voices
Full access to the live monitoring dashboard
No credit card required

A typical 1-hour stream uses roughly 30 minutes of caption time and 35 minutes of dubbed time (we meter actual speech processing time, not wall-clock time — so pauses, gameplay-only segments, and silence don't count). The Free plan gives you enough to test a full stream and experience the quality firsthand.

Pro Plan — $29/month

600 caption minutes and 300 dubbed minutes per month (~20 hours of streaming)
Up to 3 target languages
Custom voice model from a 30-second sample
RTMP relay distribution to multiple platforms
Audio mixing controls
Configurable spend limit for overage
14-day free trial

Business Plan — $79/month

Unlimited caption minutes and 1,200 dubbed minutes per month (~80 hours of streaming)
Unlimited target languages
Ultra-low latency mode (< 500ms)
Advanced voice tuning
Voice replication with emotion preservation (coming soon)
Priority support

Enterprise — Custom Pricing

Unlimited everything
Dedicated relay infrastructure
Custom API integration
SLA guarantees
White-label options

All paid plans use precision metering — we only count the seconds where our AI is actually doing work. If you're silently gaming for 10 minutes, that's 0 caption minutes and 0 dubbed minutes. You pay for what you use, and nothing more.

Paid plans also include a configurable spend limit so you're never surprised by overage charges. Set it to $0 to hard-stop at your included minutes, or remove the cap entirely for uninterrupted streaming.

Try It Today

StreamFluent is live. The free tier is available right now at streamfluent.ai. No credit card. No commitment. Just sign up, paste an RTMP URL into OBS, and stream to the world.

If you're a creator who has ever wondered what your audience could look like without a language barrier — this is your answer.

If you're a viewer who has ever clicked away from an incredible stream because you couldn't understand the language — those days are numbered.

We built StreamFluent because we believe the best content should win, regardless of what language it's in. And starting today, it can.

Your voice. Every language. Let's go.

Start Dubbing Free →

StreamFluent supports Twitch, YouTube, Kick, and any RTMP-compatible platform. Currently available in 15 languages with more being added regularly. Questions? Reach us at support@streamfluent.ai or check our documentation.

Introducing StreamFluent: The World's First Real-Time AI Voice Translation for Live Streamers is Live