Captions and Subtitles
Captions and subtitles are on-screen text of a video's spoken words, added for viewers who watch on mute or in a different language.
Captions and subtitles are text overlays that show what is being said in a video. Captions traditionally also note sound effects and speaker changes for viewers who cannot hear audio at all, while subtitles traditionally assume the viewer can hear but need a translation; on social platforms the two words are now used almost interchangeably for the same on-screen text.
They matter because a large share of social video is watched with the sound off by default, especially in public feeds and workplace scrolling, so a video without captions can lose its message in the first second. Most platforms, including TikTok, Instagram, YouTube and LinkedIn, offer automatic caption generation, and accuracy has improved, but names, brand terms, numbers and background noise still trip it up often enough that a quick manual check before publishing is worth the extra minute.
Beyond accessibility, captions keep viewers watching longer, which most ranking algorithms reward with more distribution.
Examples
- A cooking video with burned-in captions retaining viewers past the 3 second mark far better than the same clip with no text.
- An auto-generated caption mishearing a brand name in 1 out of every 10 videos, caught only by a manual review pass.
Related terms
Alt text is a written description attached to an image so screen readers can voice it and platforms can index the image for search.
Aspect ratio is the proportion between an image or video's width and height, written as two numbers such as 9:16, 1:1, 4:5 or 16:9.
Short-form vertical videos on Instagram (9:16, up to 90 seconds).