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Content accessibility matters because it gives everyone equal access. It also gives users choices for consuming your organization’s content. Accessible online content helps optimize an organization’s website for search engines. To help you implement changes that align with these recommendations, the Tool Types section outlines types of software and other digital tools to support accessibility.


It is important for museums to consider their brand standards. Jamie Vought, formerly of the Arizona Science Center, notes that the colors, fonts, document templates, etc. outlined in an organization’s branding guide may make accessibility a challenge. She encourages museums to invest the time in evaluating these materials and considering short-term and long-term plans for increasing accessibility. And those planning a rebranding should ensure that accessibility is centered in all aspects of the new brand.


All digital content, including websites, presentations, social media posts, and digital registration forms, must be readable by a wide range of audiences. Readability checkers can be used to ensure the language is not too advanced (Use Plain Language talks how to write in plain language and terms to avoid). However, the formatting of text is also critical.

  • Use left-align in all text (presentations, invitations, web content) including headings because center and full-justification is hard to read.
  • Use sentence case or title case instead of uppercase.
  • Limit the use of bold, underline, and italics to a few words or phrases. These shouldn’t be used for sentences or entire paragraphs. 
  • Use underline on links to help people find them.
  • Link a few phrases, not an entire sentence; otherwise it becomes unwieldy.


Hashtags help people tag and find content. But they can also be hard to decode or even embarrassing when they’re all in lowercase. Screen readers say all lower-case hashtags as one word. They cannot make out the different words in the hashtag when the first letter of each word isn’t capitalized. Capitalizing the first letter of each word is called camel case.

Check out these examples:

  • #godisnowhere vs. #GodIsNowHere
  • #nowthatchersdead vs. #NowThatchersDead
  • #susanalbumparty vs. #SusanAlbumParty

Test your hashtags in lowercase because not everyone knows to use camel case. You want to ensure they don’t create something embarrassing or the wrong message like these examples.

Alternative text for images

One of the easiest and most effective things you can do in content accessibility is to add alternative text to your images. They may be referred to as alt text, text alternatives, or image descriptions. Alt text describes the image as if the image doesn’t show up. The practice of writing alt text is important as some people have images turned off in a social media platform, use a screen-reader app, or have a slow internet connection. 

Alt text is not the place to enter keywords to optimize it for search engines and algorithms. The key is to be descriptive yet concise. What’s important about the image in relation to the content it supports? One image could have many interpretations. The correct one depends on the context.

One tip is not to put an entire event invitation in an image. It’s better to put the event information in the email, web page, or even in a Microsoft Word or Google Document.

Accessible PDF files

It’s hard to create fully accessible Adobe Acrobat PDF files so you should consider whether the content that would otherwise be included in a PDF file can also be shared in a more accessible way. But because we know that PDF files are so common and often hard to avoid, here’s a resource on how to create accessible PDFs from More generally, first create an accessible Microsoft Word document then convert it into an accessible PDF.

Accessible event registration 

The first step to ensure your event is accessible for attendees is to ask them what they may require to fully participate. The event registration form should have a question about accessibility requirements. One way to word the question is, “What do you require in order to fully engage in this event?” Add a deadline for the request. You’ll need at least two weeks to ensure you can line up a live captioner or a sign language interpreter.

In creating the event registration form, the key is to be descriptive yet concise. Don’t ask for too much information. This can cause frustration and cognitive overload. Check to make sure the form works using only a keyboard. To test it, press the Tab key repeatedly. The cursor should move to the next logical field. Also, make sure the cursor does not get trapped. This means you can’t get out of the box by pressing the Tab key. If you run into either problem, contact the developer or designer. How to Create an Accessible Event Submission Form contains more detailed information regarding how to design an accessible digital registration form.

All events, web pages, and apps need to have at least two modern contact or communication options. Examples of modern contact options include email, phone number, text number, chat box, and a video call with captions or a sign language interpreter. Read Communication Accessibility: It’s Time to Change How We Communicate on the importance of accessible two-way communication options and inputs.


Videos, audio clips, and podcasts need captions, transcripts, and sign language interpretation to ensure they’re accessible. Here are the best practices.


Not all people who watch captions are deaf or hard of hearing. Turning the sound off to test the captions is a starting point. But it does not replicate the experience of a person who depends on high-quality, accessible captions.

Here are nine factors to pay attention to when testing captions:

  1. Readability: Social media and captioning tools don’t always have accessible captioning styles. It’s best to use closed captions as they can be turned on and off by the user; this is where you’ll have a separate caption file. Open captions, on the other hand, is when a video has captions always visible on the screen and can’t be toggled. If the viewer can’t turn the captions on and off, then it’s most likely open captions. Use sentence case rather than uppercase.
  2. Accuracy: The captions should capture all relevant audio whether it’s said or heard. 
  3. Synchronized: The captions and dialog need to be in sync. Note that if you edit the video after a closed caption file is generated, the captions will be out of sync with the edited video.
  4. Length: The length of the captions matter. To prevent cognitive overload, aim for one to two lines of captions with no more than 32 characters per line.
  5. Position: Captions should appear on the bottom except when there’s important on-screen information, such as explanatory graphics, speaker titles, pop-up text, or credits. In this case, prevent overlap by moving either the captions or other important information to the top. Viewers need to see both captions and any on-screen information.
  6. Sound: Both music and sound should be captioned. As for sounds, if it’s not obvious from watching the visual and it’s important information, then it needs to be described. For example, if someone is bouncing a ball, it’s not necessary to caption the sound of the bouncing. However, if someone is doing a science experiment that changes the sound of the bouncing, then this change needs to be captioned. Also, note silence that’s longer than typical, otherwise viewers may think there are no captions or they stopped working.
  7. Voice changes: If someone changes their voice, then it needs to be noted in the captions. For example, captions ought to indicate when someone sounds hoarse, raises their voice an octave, or imitates a famous person.
  8. Speaker identification: When it’s not obvious who is speaking, it’s important to identify the speaker. E.g. “[Juliet] O Romeo, Romeo, wherefore art thou Romeo?”
  9. Motion: Oftentimes, the motion of captions is different between a live and recorded programs and events. For recorded programs, captions typically pop in and out. For live events, the captions often scroll up from the bottom of the screen (moving or scrolling). While it is hard to avoid scrolling captions during live events, pop-in captions are a better viewing experience and should be used whenever possible. 

To learn more about captioning and best practices, refer to the Captioned Guide, Frequently Asked Questions About Captions, and understand why best practices matter in the Side-by-Side Captioned Videos.


When it comes to captions or transcripts, you want to offer both. It’s relatively easy to create a transcript from the caption file. YouTube does it automatically. Here are the main reasons why you want both:

  1. Transcripts are accessible for people using refreshable Braille displays. They’re also accessible for screen readers. Captions are not accessible or easy to use for these assistive technologies. You can work around this on social media by adding the transcript into the post or comments. Some content management systems have plug-ins that automatically add a transcript to a video when you provide captions. 
  2. Captions can move too fast for some viewers. Captions show one or two lines at a time. Some people need to go back or see more lines at a time. Because they provide different user experiences, you don’t want to skip captions and only use transcripts. 
  3. Transcripts allow people to search and scan the content. Someone may be looking for a specific part in a video or podcast. It’s not easy to search the video or audio for the content you want. The transcripts solve this problem. However, transcripts require checking and editing. It is common for them to have long blocks of text without paragraph breaks or only have paragraph breaks when the speaker changes. 
  4. Captions have less cognitive overhead. You don’t want to drop captions for transcripts because transcripts are harder to read and follow. It can be easy to lose your place. Captions make it easier to catch more of what’s happening in the video.
Sign language

There are many sign languages. However, those in the United States and Canada tend to use American Sign Language (ASL). Some parts of Canada, particularly Quebec, use Langue des Signes Québécoise (LSQ). For more information, refer to Sign Languages of Canada.

As with all professions, sign language interpreters have different specialties and there are interpreters who specialize in science, medicine, music, and engineering. To the extent possible, the interpreter should be familiar with the material covered and be provided with preparatory material in advance. Here are tips for hiring a sign language interpreter

When you have live video, ensure the sign language interpreter is always fully visible. Their hands should never be cut off outside of the viewing window. Their background, clothing, and lighting also affect the viewing experience. For more resources on sign language interpreters, in the United States, refer to Registry of Interpreters for the Deaf, Inc and in Canada refer to the Canadian Association of Sign Language Interpreters

Audio description

In most videos, a lot happens in visuals that tell the story without any dialogue, so those not seeing the screen can miss out. Audio description describes the visuals to help those not watching know what is happening. The Audio Description Project tells you everything you need to know about audio descriptions. YouDescribe is a free website and iOS app where sighted volunteers write and record audio description tracks for videos on YouTube. This lets viewers watch YouTube videos with audio description. 

Learn more about accessible media

Read icon. Read: Making Audio and Video Accessible discusses accessible media.

Read icon. Read: How to Create an Accessible Podcast covers the steps on how to do this.

Read icon. Read: Writing Alt Text for Data Visualization has suggestions for how to write alt text for charts, maps and other tools frequently used in science communication.

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