Back in high school (which, let's be honest, was a very long time ago), I took a few years of Spanish. I could conjugate verbs, write essays about my spring break trip to Mexico, and even hold basic conversations. But there was one thing that always tripped me up: listening comprehension. When our teacher would talk for any amount of time at normal speed, I'd be completely lost. The words just flew by too fast for my brain to process.
The only way I could follow along was if I had the transcript in front of me. Suddenly, everything clicked. I could see "¿Dónde está la biblioteca?" written out, and my brain would connect the dots between the sounds and the meaning. Reading the words while hearing them was like having a bridge between what I knew and what I was trying to understand.
Fast forward to today, and I know that experience isn't unique to language learners in a classroom. Whether you're a non-native speaker trying to follow a product announcement, someone who's hard of hearing, or you’re just trying to watch a video on mute in a noisy coffee shop, captions provide that same crucial bridge. And when it comes to live streaming, that bridge needs to be built in real-time.
That is why I'm so excited about what we're announcing today: Mux Video live stream auto-generated captions now supports six languages: English, French, German, Italian, Brazilian Portuguese, and Spanish. We're already able to auto-generate captions for on-demand video content in multiple languages, but now live streaming can do the same. Whether you're streaming a cooking show from Rome, a fashion show from Paris, or a music festival from Madrid, your global audience can now follow along in real-time.
The live streaming accessibility landscape is changing
If you've been paying attention to accessibility regulations, you've probably heard about the European Accessibility Act (EAA), which came into effect in June 2025. This directive requires many digital services, including streaming platforms, to be accessible to people with disabilities. Live captions aren't just a nice-to-have feature anymore — they're becoming a requirement in many jurisdictions.
But beyond compliance, it’s important to make live content accessible to everyone. When you add captions to your live streams, you're not just helping viewers who are deaf or hard of hearing. You're helping people watching on mute in quiet environments, non-native speakers following along, and making it easier for AI to process your content.
The technical challenge of live captions
Live captions present a unique set of challenges compared to on-demand content. With VOD assets, we can process the file in large chunks to give the model more context and take our time to get things right. Live streaming is different — everything happens in real-time and there are no do-overs.
For live captions to work well, our speech recognition models need to process audio as it comes in, make predictions about what's being said, and generate captions with minimal delay. All while handling the unpredictability of live audio: background noise, multiple speakers, accents, and the occasional technical glitch. The underlying models we use have been optimized specifically for live streaming scenarios, balancing accuracy with the low latency requirements that make live captions useful.
Enable live captions in multiple languages
Getting started with multilingual live captions is straightforward. When you create a live stream, you can now specify the language being spoken for auto-generated captions. We will transcribe the content based on the language you specify (we don’t auto-translate yet but keep an eye on this space for future announcements).
// POST /video/v1/live-streams
{
"playback_policy": ["public"],
"generated_subtitles": [
{
"language_code": "es",
"name": "Spanish (auto)"
}
]
}We support these language codes:
- en - English
- fr - French
- de - German
- it - Italian
- pt - Brazilian Portuguese
- es - Spanish
You can also add captions to an existing live stream using the tracks API:
// PUT /video/v1/live-streams/{LIVE_STREAM_ID}/generated-subtitles
{
"generated_subtitles": [
{
"name": "Français (auto)",
"language_code": "fr"
}
]
}The captions will appear in Mux Player and any other HLS-compatible player that supports live captions. Just like with our on-demand captions, you can customize the styling and positioning to match your brand.
Transcription vocabularies allow you to provide a personalized list of technical terms (e.g. CODEC) and proper nouns. The existing transcription vocabulary feature can be used with the new languages. You can share a vocabulary across your languages but we recommend you create a vocabulary per language to optimize the accuracy of the generated captions.
Same great value, expanded reach
These new language options are available at the same price as English captions for live streams. We're not adding language surcharges or premium tiers — we believe accessibility shouldn't cost extra.
This pricing reflects our philosophy of making video more accessible and affordable. Whether you're a startup streaming their first product demo or an application broadcasting to a global audience, you can add captions in any of these five additional languages without worrying about budget implications.
What's next?
This launch represents the first phase of our expanded language support for live captions. We'll be working on adding support for more languages and we're continuously improving the accuracy and performance of our existing models.
Get started today
Multilingual live auto-generated captions are available today for all Mux Video customers. No special setup or account changes are required, just specify your target language when creating or updating your live stream.
Whether you're preparing for EAA compliance, expanding to new markets, or simply want to make your content more accessible, now is the perfect time to add captions to your live streams.
Check out our documentation for the full details on implementing live captions, and let us know what languages you'd like to see supported next.
¡Que tengas un buen día! Bonne journée ! Buona giornata! Have a great day!
