--- title: "Captions (Live)" url: "https://barrierefreihochzwei.de/en/wcag/1-2-4-captions-live" language: "en" description: "Live streams and webinars with sound need real-time captions. Find out what WCAG 1.2.4 requires and how to put live captioning into practice." published: "2025-01-01T08:00:00+01:00" updated: "2026-10-15T09:41:59+02:00" --- # Captions (Live) When real time has to work for everyone. - **Erfolgskriterium:** 1.2.4 - **Prinzip:** Perceivable - **Konformitätsstufe:** Level AA - **Erklärung beim W3C:** [www.w3.org/WAI/WCAG22/Understanding/capt...](https://www.w3.org/WAI/WCAG22/Understanding/captions-live.html) Success criterion 1.2.4 # 1.2.4 Captions (Live) Level AAPerceivable When real time has to work for everyone. ## 1. What is the goal of this criterion? Conferences, webinars, product launches or news streams – live video has become part of everyday life. It offers closeness, immediacy and direct interaction. But if you can’t hear, you’re left out when there are no captions. That’s why WCAG Success Criterion 1.2.4 at Level AA requires real-time captions for live broadcasts with sound. This makes live content understandable for deaf and hard of hearing people too – at the same time as everyone else. ## 2. What exactly does it require? Live is live – and that’s exactly what makes accessibility harder than with prerecorded content. With produced videos there’s time to create captions carefully; here you need a real-time solution. Success Criterion 1.2.4 requires all audio in a live video to be captioned live: - All live audio content in synchronized media (sound plus picture, such as video streams) needs captions. - The captions appear as close as possible to the moment the words are spoken. - As with prerecorded video, important non-speech information is part of it too: music, sounds, speaker changes. On scope: according to the W3C’s Understanding document, the criterion is aimed at broadcasts such as live streams and webcasts. It isn’t meant to require captions for video calls between individuals through a web app. So it’s about live presentations where one or more people broadcast – not private conversations. ## 3. Why does it matter for accessibility? A live stream without captions is like watching a play through a pane of glass: if you can’t hear the sound, you miss everything. And that affects more people than you might think – besides deaf and hard of hearing people, it also helps many who: - are in a noisy environment, - can’t use headphones, - speak a different first language, - or simply prefer reading to listening. **Live captions make sure that:** - everyone can follow along at the same time – regardless of their hearing, - important information arrives in real time, for example in emergencies or live announcements, - events such as conferences, talks or product launches become inclusive, - communication stays traceable – even after the stream, if captions are archived. ## 4. How to meet the criterion Live captions sound technically demanding – but with the right services and tools, they’re very doable today. An overview: ### 1. Professional real-time captioning (CART) - CART stands for “Communication Access Realtime Translation”: trained captioners transcribe what’s said in real time – on site or remotely. - Very accurate – ideal for important events, public appointments or specialist conferences full of technical terms. ### 2. Automatic live captions - Platforms such as YouTube Live, Microsoft Teams, Zoom or Google Meet offer automatic captions. - Upside: fast and affordable. - Downside: not always accurate – especially with jargon, accents, fast speech or several people talking at once. Test in advance whether the quality is good enough for equal participation. ### 3. A combination of both - Automatic recognition with real-time human correction can improve quality considerably. - For planned segments with a fixed script, you can play in prepared captions and add live captions for the spontaneous parts. ### Tips for better accessibility - Identify speakers clearly – for example “\[Host\]” or “\[Participant 2\]”. - Show non-speech sounds too: \[applause\], \[music\], \[silence\]. - Keep background noise and cross-talk to a minimum – that helps both people and machines. - Make captions easy to read (font size, contrast, position). Once the stream is over, the recording falls under [Captions (Prerecorded)](https://barrierefreihochzwei.de/en/wcag/1-2-2-captions-prerecorded) – a good opportunity to correct the live captions. For audio-only live streams without video, [Audio-only (Live)](https://barrierefreihochzwei.de/en/wcag/1-2-9-audio-only-live) applies at Level AAA. ## 5. Why this criterion matters for businesses Accessible live events aren’t a luxury but a real plus – in several ways: ### 1. Wider reach Many people follow content without sound – on the train, in the office, at events. Live captions let you reach them anyway. ### 2. More inclusion You make your live content accessible to people with hearing loss – and send a clear signal for digital participation. ### 3. Better understanding People with a different first language or cognitive disabilities also find content easier to understand and follow with captions. And then there’s the law: since 28 June 2025, the European Accessibility Act has applied to many consumer products and services; Germany implements it through the Barrierefreiheitsstärkungsgesetz (BFSG). The benchmark is EN 301 549, which refers to WCAG 2.1 Level AA for web content – 1.2.4 is an AA criterion and therefore part of it. Public sector bodies have their own obligations. (General information, not legal advice.) ## 6. The success criterion in the W3C’s words > **Success Criterion 1.2.4 Captions (Live) (Level AA)** > > Captions are provided for all live audio content in synchronized media. In short: every live stream with picture and sound needs real-time captions. **Official explanation from the W3C** The W3C explains every success criterion in depth – with intent, examples and techniques. [Understanding 1.2.4](https://www.w3.org/WAI/WCAG22/Understanding/captions-live.html) ## More criteria from “Perceivable” [ 1.1.1 Level A ### Non-text Content When images need words. ](https://barrierefreihochzwei.de/en/wcag/1-1-1-non-text-content) [ 1.2.1 Level A ### Audio-only and Video-only (Prerecorded) When podcasts and silent videos need a second form. ](https://barrierefreihochzwei.de/en/wcag/1-2-1-audio-only-and-video-only-prerecorded) [ 1.2.2 Level A ### Captions (Prerecorded) When videos need to make sense without sound. ](https://barrierefreihochzwei.de/en/wcag/1-2-2-captions-prerecorded)