B-Roll refers to supplementary footage used to support, illustrate, or cut away from the main action in a video. While A-roll typically features the primary subjects, such as an interview or scripted scene, B-roll provides visual context, transitions, and texture that make the overall edit more dynamic and engaging.

In documentary filmmaking, B-roll might include shots of a location, close-ups of objects being discussed, crowd scenes, or environmental footage that helps paint a picture around the main narrative. In commercial and social media production, B-roll often carries the majority of the visual storytelling, with voiceover or music playing over it rather than on-camera dialogue.

AI video generation tools have made B-roll creation far more accessible. Rather than sending a camera crew to capture supplementary footage, creators can generate contextually appropriate B-roll clips using text prompts. Platforms like Morphic allow users to generate video assets for use as B-roll directly within their editing workflow, significantly reducing production time and cost for video projects of all sizes.