Caption Accuracy: Timing and Synchronization
KENNESAW, Ga. | May 13, 2026
Caption content that is technically correct can still create confusion if it is not synchronized properly with the visual content.
For busy instructors and content creators, it can often be tempting to think of accessibility features as something to simply check off. “Alt text on images? Check! Captions? Check!” But accessibility is also about quality. If alt text or captions are present but not accurate or descriptive enough, some people accessing your content will be at a disadvantage.
Accessibility checkers can tell you if an image in a document or a web page has alternative text, but they may not be able to tell you how descriptive that alternative text is or whether it communicates what you intended for the image in context. This is why we always recommend reviewing the quality of alternative text even if an accessibility checker says it’s ok.
Similarly, when it comes to video captions, most of us already understand the importance of reviewing captions for accuracy. A single misunderstood term may cause a student to misunderstand an assignment or an important concept. It could also confuse a student applying for financial aid or important research grants.
But what many people may not realize is that caption accuracy goes beyond grammar—it also involves the timing of the captions. Captioned content that is technically correct can still create confusion if it is not synched properly with the visual content. A few examples include:
- Captions that run ahead or behind visual content. Imagine watching a demonstration of a process or an experiment and the audio does not line up with what’s happening on the screen. This can happen in the captioning process as well.
- Captions with incorrect sentence breaks. Auto-captioning often has to “guess” at our sentence structure as it listens. It may falsely break up an idea or merge two sentences together incorrectly.
- Captions that overlap or blend content. Auto-captioning may produce correct words and grammar but still struggle with focus. If the speaker is pointing out specific items on an image, diagram, or model and the captions appear on the screen at the same time, it may cause confusion for some viewers. Our example video, Caption Timing Demonstration: Midwestern States demonstrates here. For the best perspective watch without sound.
To learn more about captioning and media accessibility, visit DLI’s page Media Accessibility: Captions and More. Similarly, if you need help reviewing or editing captions on a video, contact DLI through the DLI Service Portal.
