Captions and subtitles for member videos with AI

Captions are one of the most useful things you can add to your video library. Members who are deaf or hard of hearing depend on them. Members watching on a train, in an open office or beside a sleeping baby watch with the sound off. Members whose first language is not yours follow along more easily when they can read as well as listen. Captions also help everyone catch a technical term or a name they might otherwise mishear.

AI makes captioning fast, which means there is no longer a good reason for a membership video to go without. But automatic captions are a first draft, not a finished product, and inaccurate captions can mislead the very members who rely on them most. This guide shows you how to get captions quickly and make them right.

Captions, subtitles and transcripts: a quick guide

These words are often used interchangeably, but they mean slightly different things:

• Captions show the spoken words in the same language and, ideally, important sounds such as [laughter] or [music]. They are written for people who cannot hear the audio.
• Subtitles usually translate the speech into another language for people who can hear but do not understand it.
• Closed captions can be switched on and off by the viewer. Open captions are burned into the video image and always visible.
• A transcript is the full text on the page, without timing.

Closed captions are usually delivered as a small text file alongside the video. The common formats are SRT and VTT: plain text files that list each caption line with a start and end time. If your membership platform's video player or your video host accepts one of these, you can upload a caption file for every video.

Where AI captions come from

You probably already have access to automatic captions. Video hosts such as YouTube and Vimeo can generate them, editing tools such as Descript and Adobe Premiere Pro can create them from speech, and dedicated transcription tools can export caption files. If you already produce transcripts, as described in transcribing recordings with AI, you are most of the way there.

Choose a tool that lets you edit the captions easily and export them as SRT or VTT, so you are not locked into one host. For recordings that include members, check the tool's data and training settings and use a business plan.

Why automatic captions are not finished captions

Automatic captions can be impressively good on clear audio and still get the important things wrong. Common problems include:

• Misheard names, product names and technical terms.
• Numbers, measurements and doses transcribed incorrectly.
• Missing or wrong punctuation, which changes meaning.
• No indication of who is speaking in a conversation.
• No sound descriptions, so a viewer misses the music cue or the audience laughing.
• Lines that flash by too quickly to read.

For a hypothetical membership such as Steady Hands Physio Network, which teaches rehabilitation exercises to physiotherapists, a caption that says “fifteen repetitions” when the presenter said “fifty” is not a small typo. It is wrong information delivered to the member who relied on the captions. That is why a person must review them.

An AI-assisted review workflow

You can use AI to speed up the review as well as the draft. A workflow that works for many small teams:

1. Generate the captions in your chosen tool.
2. Pre-check them with an AI assistant, using a glossary of your terms, to flag likely errors.
3. Watch the whole video with captions on, and fix what is wrong.
4. Adjust any lines that are too long or too quick.
5. Export and upload the caption file, then spot-check it in the player.

For step two, a prompt like this helps:

Below is a caption file for a video about [topic] for [describe your members]. Here is a glossary of names and terms that appear in the video: [list names, terms and correct spellings]. Please list every caption line where a word looks like a mis-transcription of a glossary term, where a number might be wrong, or where punctuation changes the meaning. For each, give the timestamp, the current text and your suggested correction. Do not rewrite the file and do not change any timestamps. Caption file: [paste caption file]

A useful result is a short list of suspect lines, not a rewritten file. You still make every correction yourself, while watching the video, because only the audio can confirm what was really said.

Set a simple caption style

A short caption style sheet keeps your library consistent, especially if more than one person edits captions:

• Keep each caption to one or two short lines.
• Leave captions on screen long enough to read comfortably.
• Label speakers when it is not obvious who is talking.
• Describe meaningful sounds in square brackets.
• Keep the speaker's words. Remove filler such as “um,” but do not paraphrase.
• Use your glossary spellings every time.

For short social clips, open captions burned into the video are common. For your members' library, closed captions are usually better because viewers can turn them off or adjust their size.

Make captions part of your accessibility promise

Captions are one piece of making your membership usable by everyone. Tell members that videos are captioned, and give them an easy way to report a caption error. A member who takes the trouble to point out a mistake is doing you a favor, so thank them and fix it quickly. For the broader basics, see accessibility basics every site owner should know.

Your first steps

• List your ten most-watched member videos and check which have captions.
• Write a glossary of names and terms that appear in your videos.
• Generate captions for one video and run the pre-check prompt.
• Watch the whole video with captions on and correct every error.
• Write your caption style sheet and share it with anyone who helps.
• Make captions a standard step before any new video is published.