Switch on almost any streaming service, television channel or social video and you will see a small menu offering subtitles, captions or both. If you have ever wondered what closed captions are and whether they are just another word for subtitles, you are not alone. Producers, marketers and training teams ask the same question every week, and the answer affects budgets, accessibility and how far a video can travel.
What are closed captions?
Closed captions are a text version of the audio in a video, shown on screen and timed to match what is being said. The word "closed" means the viewer can switch them on or off, unlike open captions that are burned permanently into the picture. Crucially, captions describe more than speech. They also note meaningful sounds such as a door slamming, music building or a speaker laughing, because they were designed for viewers who cannot hear the soundtrack.
The technology dates back to broadcast television, and the history of closed captioning on Wikipedia traces how a service built for deaf and hard of hearing audiences became a standard feature of nearly every screen we use.
Closed captions vs subtitles
In everyday speech the two terms get swapped, but in the industry they mean different things. Subtitles assume the viewer can hear the audio and simply need the dialogue in a language they understand. A French film with English subtitles is the classic example. Captions assume the viewer may not hear anything at all, so they include speaker labels and sound cues as well as dialogue.
In the UK, the picture is slightly muddier, because broadcasters and platforms often use the word "subtitles" for both. That is why you will see "subtitles for the deaf and hard of hearing" in programme guides. The practical test is simple: if the text includes descriptions of non-speech sounds, you are looking at captions, or what the trade calls SDH subtitles. For a deeper comparison of the two formats and when each one makes sense, this guide to closed captions and subtitles sets out the differences in plain language.
Who benefits from closed captions?
Accessibility is the original reason and it remains the strongest one. Millions of people in the UK live with some degree of hearing loss, and captions are what make video usable for them. But the audience is much wider than that. Viewers watch on trains, in open offices and in waiting rooms with the sound off. Language learners use captions to connect spoken and written words. People with attention or processing differences often find that text on screen helps them follow along.
For businesses, the commercial case follows naturally. Captioned videos tend to hold attention for longer, and the text can be indexed or repurposed as a transcript, a blog summary or social clips. A fuller explanation of why this matters is available in this article on the importance of closed captioning, which looks at reach and inclusion from a localisation point of view.
What good captions look like
Quality is where amateur work gives itself away. Good captions appear in sync with the speaker, stay on screen long enough to read comfortably and break lines at natural phrases rather than in the middle of a thought. Most guidelines suggest no more than two lines at a time, with a reading speed that an average viewer can manage without rewinding. Speaker names appear when it is not obvious who is talking, and sound cues are short and neutral, such as [applause] or [phone rings].
Accuracy matters just as much as timing. Automatic speech recognition has improved a great deal, but it still stumbles over accents, names, technical terms and overlapping voices. For anything public or regulated, a human review is the sensible final step. The W3C guidance on captions and subtitles explains the principles behind accessible captioning and is a useful reference when you brief a supplier.
How to add closed captions to your videos
There are three common routes. The first is to upload a caption file, such as an SRT or VTT file, alongside your video on platforms that support it. This keeps the text separate and editable, and it lets viewers toggle it on and off. The second is to use a platform's automatic captions and correct them by hand, which is quick but needs a careful read-through. The third is to commission a professional subtitling team, who will transcribe, time and quality-check the captions and can deliver them in several languages at once.
If you plan to reach international audiences, think about translation early. Captions written well in the original language are far easier to translate than rushed ones, and a single clean transcript can feed several subtitle tracks. Agree the style rules before work begins, including how to handle on-screen text, songs and brand names.
Do you need captions or subtitles?
Choose closed captions when accessibility is the priority, which includes most UK broadcast, education and public sector content. Choose subtitles when the main goal is translation for viewers who can hear the audio. Many productions end up needing both, delivered as separate tracks so that each audience gets what it needs.
Whatever you decide, the best moment to plan is before the edit is locked. Captions are cheaper, faster and more accurate when they are part of the production schedule rather than a rescue job at the end, and your viewers will notice the difference long before they notice the text itself.