Closed Captions: Everything You Need to Know

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Closed Captions: Everything You Need to Know

Posted August 21, 2024

AudioEye

Posted August 21, 2024

Video player showing an image of a woman pointing to an accessibility icon. 'Closed Captions' is written across the bottom of the screen.
Video player showing an image of a woman pointing to an accessibility icon. 'Closed Captions' is written across the bottom of the screen.

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Closed captioning enhances the viewing experience for individuals with both permanent and situational disabilities. Discover how incorporating closed captions makes your content more inclusive and engaging for a diverse audience below.

Closed captions are an essential accessibility feature for users who are Deaf or hard of hearing — but like many accessibility features, captions are helpful for all users, regardless of their abilities. To put it plainly: If your internet videos don’t have captions, you’re missing a major opportunity to keep your audience engaged. 


And in order to create video content that complies with the Americans with Disabilities Act (ADA) and other laws, you’ll need to make sure your captions are consistent and accurate. In this article, we’ll explain why closed captions are so important — and how they can help you reach more people.

What are Closed Captions?

Captions are text alternatives to the audio portion of multimedia content. In this article, we’re primarily talking about the audio content in videos, though slideshows and animations may also have important audio (and should also include captions). 

To function as a true “text alternative,” captions should include all of the dialogue from the content, along with other auditory information that cannot be understood through visuals alone. That includes important sound effects, musical cues, and the name of the speaker (if more than one speaker is on screen).  

Who Benefits from Closed Captions?

Closed captions are primarily intended for users who are Deaf or hard of hearing. That’s an enormous part of your audience; by one estimate, about 30 million Americans age 12 or older have hearing loss in both ears. 

Captions also benefit a wide range of other users, including people:

  • Who are learning a second language.
  • With conditions that affect their short-term memory.
  • With conditions that affect their ability to pay attention.
  • Who browse the internet with their sound turned off.

Closed Captions vs. Subtitles: What’s the Difference?

The only difference between closed captions and subtitles is the amount of information included within the text. 

To recap, captions include all relevant information from the audio track. That includes spoken words and non-speech elements: sound effects, musical cues, and anything else that imparts information. 

Subtitles are intended for people who can hear the audio, but cannot understand the dialogue. For example, if you’re watching a Spanish film and you don’t speak Spanish, you might use subtitles; the text will display the dialogue in English, but won’t include other audio information. 

Since subtitles assume that the viewer can hear sound, they may not indicate the speaker's identity. They’re also typically located on the bottom of the screen, while closed captions might appear at the top or middle of the video window, depending on the user’s preferences. 


While the terms captions and subtitles are often used interchangeably, captions are essential for accessibility. Subtitles are not as helpful for accessibility (though they’re preferable for video programming for some users).

What’s the Difference Between “Closed Captions" and “Open Captions?”

By definition, closed captions can be turned on or off. They’re not “burned in,” or pre-rendered with the rest of the video. Pre-rendered captions are also called open captions, and they’re less useful for accessibility. 

Why? In short, plain text can be adapted to the user’s preferences. By encoding closed captions as actual text, you give people the opportunity to read them with assistive technologies (such as screen readers), translate the text to different languages, or change the font size and typeface. 

Pre-rendered captions cannot be changed or turned off; they’re a permanent part of the video.

Legal document with accessibility icon on the top; a gavel is to the left of the document and two large books on the right.

The ADA’s Requirements for Closed Captions

Titles II and III of the ADA prohibit discrimination on the basis of disability. According to the Justice Department, the ADA applies to online content (and by extension, online videos).

People with disabilities may file lawsuits against businesses that fail to fulfill their obligations under the ADA. Video accessibility issues are often cited in ADA litigation, including a landmark digital accessibility case that accused Netflix of failing to provide captions for streaming content.

To test online content for ADA compliance, the Justice Department recommends using the Web Content Accessibility Guideline (WCAG) 2.1 Level A/AA. WCAG includes two criteria that specifically require captions: 

  • WCAG 2.1 SC 1.2.2, “Captions (Prerecorded)”: Requires captions for all pre-recorded audio in synchronized media, except when the media is a media alternative for text and is clearly labeled as such. 
  • WCAG 2.1 SC 1.2.4, “Captions (Live)”: Requires captions for all live audio content in synchronized media. This is specific to live programming, webinars, and other public presentations — it doesn’t apply to two-way calls on services like Zoom or other internal communications.

Live captions are usually created by real-time captions services or Communication Access Realtime Translation (CART) providers. However, for pre-recorded videos, you can certainly write and encode the captions yourself (we’ll discuss the best practices later in this article). 

It’s important to note that closed captions aren’t the only way to make videos more accessible. WCAG also requires audio descriptions, and many other guidelines are applicable to multimedia (for example, the WCAG requirements for color contrast and use of color). 


To learn more about WCAG and video accessibility, read: 6 Tips for Creating Accessible Videos

FCC Requirements for Closed Captions

The Federal Communications Commission (FCC) also regulates some internet video content under the 21st Century Communications and Video Accessibility Act (CVAA).

Enacted in 2010, the CVAA requires captions for all pre-recorded television programs published on the internet, provided that those programs are not substantially “edited for the internet." In this context, “edited" means making meaningful changes (such as adding or deleting scenes). 

These closed captioning requirements are applicable to broadcasters and distributors. The FCC may enforce the law through fines. In 2021, Pluto Inc. and ViacomCBS paid a $3.5 million civil penalty for failing to comply with the CVAA.


To learn more about accessibility in broadcasting, read: Broadcasting Accessibility with Larry Goldberg

International Requirements for Closed Captions

Worldwide, many non-discrimination laws have specific requirements for internet content. The European Accessibility Act (EAA), Accessibility for Ontarians with Disabilities Act (AODA), and European Union Web Directive all use WCAG as a framework — and captions are necessary for WCAG conformance.


To learn more about international requirements for web accessibility, visit our International Accessibility Law Repository.

A laptop is open and displaying a website, next to icons for deafness and accessibility

What are the Benefits of Using Closed Captioning?

Compliance is important, but it’s not the only reason to use closed captions. By providing text, you can reach more viewers and improve your website's functionality. 

One study from Verizon Media found that 59% of consumers watch online videos with the sound off while in public places, and 80% of consumers are more likely to watch an entire video when captions are available.

Just as importantly, you can make a bigger impression on your users. Studies show that captioning videos improves comprehension of, attention to, and memory for the video — all important factors when you’re using video to build your brand.

Other reasons to include captions with your videos:

  • Improved organic traffic: Closed captions are crawler-friendly, so they’re great for search engine optimization (SEO). Including key terms in your captions can help you earn higher positions in search engine rankings.
  • A better user experience: Closed captions give your users options. If they’re in a public place or they don’t feel like listening, they can still engage with your content. 
  • Easy implementation: Like many accessibility improvements, closed captions cost little or nothing to implement.

Best Practices for Closed Captioning

Online videos must include captions, so get into the habit of thinking about captions when drafting scripts and editing your content. Here are a few tips to help you avoid common mistakes:

Focus on Accuracy

WCAG requires captions to be “fully accurate,” so captioning quality is important. Hard-of-hearing viewers should be able to enjoy an equivalent experience — and if your captions are only 70% accurate, those viewers will quickly become frustrated or confused. 

Remember to caption everything important and relevant. That includes:

  • Dialog, including distorted or inaudible dialog.
  • Identification of the speaker (when multiple people are onscreen or speaking simultaneously).  
  • Important information about the speaker. For instance, if a person suddenly starts speaking French, you’d want to include that info within the text.
  • Sound effects, musical cues, and background noise. Use brackets to indicate non-dialog sounds. 
  • Lack of sound, if the silence affects the meaning of the video content. 

Use brackets for non-dialog sounds and parentheses to indicate who’s speaking.

Don’t Include Filler Words Unless They’re Important

Full accuracy does not mean that you have to include every syllable uttered by every speaker. You don’t need to include filler words (such as “um" or “ah") unless they affect the meaning of the sentence. 


For example, if a politician responds to a question with, “We’re, uh, looking into it,” the filler word (“uh") might be important if the politician is dodging the question.

But when filler words don’t provide important context, it’s safe to leave them out. Otherwise, your captions may be difficult to read.

Sync the Captions to the Video

If your captions aren’t synced with the video playback, they’re not nearly as useful. Viewers might not understand who is speaking or what they’re speaking about — after all, your video includes visual content for a reason.

Use High-Quality Audio

Some people with hearing difficulties will use captions. Others won’t, so make sure that your audio is as clear as possible. Limit background noise wherever you can and use compression to keep the volume consistent. 

High-quality audio can also increase the accuracy of speech recognition tools that provide automatic captioning (which we’ll discuss in a moment).

Choose the Right Tools

If adding captions to your videos takes hours and interrupts your workflow, you probably won’t do it consistently. Invest in high-quality video editing software that will make the process easier. 

Look for a tool that supports exporting captions or embedding them within the media. Exporting the captions as a separate file may save you time if you’re uploading videos to multiple online platforms.

How to Add Captions to Videos

There are a few ways to generate captions. Each method has advantages:

  • Manual transcription: The most accurate way to create captions is to manually type each word, then synchronize the script with the video. Unfortunately, this can be a time-consuming process, particularly if you’re working with a large library of videos.
  • Automated transcription: Automatic captioning services can provide a quick first draft, but they’re prone to errors. One study found that YouTube’s automatic captions are only about 60-70% accurate.
  • Live captioning services: Dedicated transcription services provide fast, accurate results, but they’re more expensive than the other options. 

It’s perfectly fine to use automatic captions as a first draft. However, as we’ve discussed, captions must be accurate to be useful. In some cases, a single mistyped word can ruin your message, so review the output every single time.

After editing for accuracy and synchronizing with the video, you can export and upload your caption file. The format and process will vary depending on the video service you’re using. The most common caption formats include:

  • SubRip Subtitle (SRT), a free, widely supported format compatible with YouTube, Facebook, Windows Media Player, and many other video platforms.
  • Distribution Format Exchange Profile (DFXP), frequently used for Flash videos.
  • Web Video Text Tracks (WebVTT), used for HTML5 video players.
  • Scenarist Closed Captions (SCC), commonly used for broadcasts.

Alternatively, you can write your captions after uploading your video by using the built-in tools of your hosting platform. For example, YouTube provides automatic captions, which creators can edit for accuracy.

What if My Video Service Doesn’t Support Closed Captions?

If possible, use a video player or distributor that does support captions. YouTube, Vimeo, and other major services have robust support for assistive technologies, and many of those services provide tools to help creators upload and synchronize their captions.

If you don’t have the option to switch to another service, pre-rendered (or open) captions are acceptable. You can also provide a hyperlink to a captioned video or a transcript.

A stylized web page that shows a series of videos with play buttons, next to an accessibility icon

Master Captions and Video Accessibility with AudioEye

Captions help you reach more people and provide viewers with a better, more flexible experience. While you’ll need to spend some time learning the best practices and synchronizing the text, it’s time well spent, particularly if you’re marketing your business through video.

Other web accessibility improvements are just as important (and just as beneficial). AudioEye can help you build a strategy to meet WCAG’s requirements — not just with videos, but across all types of digital content.

Our hybrid approach pairs human guidance with powerful automation, giving you everything you need to create a truly inclusive website. We also provide tools for developers, dedicated accessibility training, and other resources to help businesses start thinking about accessibility from day one.


Get started with a free accessibility scan, or schedule a demo to learn more.

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