Skip to main content
B-roll is supplementary footage that plays over your primary talking-head shot. It illustrates what you’re saying, breaks up the monotony of a static shot, and keeps viewers watching. Well-placed B-roll is one of the biggest separators between amateur and professional-looking video. This guide covers all three ways to add B-roll in Captions: importing your own media, using stock, and generating with AI.

​
The three sources of B-roll

The most authentic option. Screen recordings, product demos, behind-the-scenes clips, photos from your camera roll: anything that visually supports what you’re saying.Best for: personal brands, product demos, tutorials, any content where showing your specific context matters.
Captions has a built-in stock library with photos, videos, GIFs, and stickers. Searchable and free to use.Best for: general concepts, supplementary visuals, quick fills when you don’t have specific footage.
Type a prompt and generate a custom image or short video clip. Powered by multiple AI models including Flux, Imagen, DALL-E, Pika, Ray, and more.Best for: original, on-brand visuals; concepts that are hard to find in stock libraries; maximum creative control.

​
Adding B-roll manually

1

Position your playhead

In the timeline, move to the moment where you want B-roll to appear.
2

Tap Media Overlay

In the editor toolbar, tap Media (or Media Overlay).
3

Choose your source

  • Import: select from your camera roll or files
  • Import → Stock: search the stock library for photos, videos, GIFs, or stickers
  • Generate: enter a prompt to generate a custom image or video clip
4

Place and resize

After adding the media, it appears as an overlay in the timeline. Drag it to position it over the right moment. Pinch to resize. Move it on the canvas by dragging with one finger.
5

Set the duration

Drag the start and end handles in the timeline to adjust how long the B-roll appears.

​
Generating B-roll with AI

1

Tap Media → Generate

Open Media Overlay and tap Generate.
2

Choose image or video

Select whether you want a still image or a short video clip. Video clips are more engaging but take longer to generate.
3

Write your prompt

Describe what you want. Be specific:
  • ❌ “a person using a phone”
  • ✅ “close-up of hands typing on a smartphone screen, warm natural lighting, shallow depth of field”
Specific prompts produce dramatically better results.
4

Choose your AI model

Different models have different strengths. For photorealistic images: Flux 1.1 Pro, Google Imagen 3, or DALL-E 3. For stylized or illustrated looks: Ideogram. For video: Pika 2.2 or Luma Ray 2.
5

Generate and place

Tap Generate. Preview the result and regenerate if needed. Once you’re happy, place it in the timeline.
AI-generated images you create in one project are saved and available to reuse in future projects, so you don’t need to re-generate the same visuals every time.

​
Editing B-roll after placing it

Tap any media overlay in the timeline to edit it:
  • Position presets: Caption Aware (auto-repositions so B-roll doesn’t cover captions), Top Half, Bottom Half, Full Screen, Freeform
  • Transitions: Fade, Pop, Zoom, Scale, Slide Left, Slide Up, or None
  • Animate: for still images, tap Animate to add slow zoom or pan motion
  • Replace: swap the media with a different image or clip
  • Split: split the media overlay at the playhead

​
Pro tips

  • Use Caption Aware positioning. It automatically repositions B-roll so it doesn’t cover your captions, which saves time and looks more polished.
  • Animate still images. A slow Ken Burns zoom on a photo looks significantly more professional than a static image just sitting on screen.
  • Match the B-roll to the speech. B-roll works best when it visually illustrates exactly what’s being said at that moment, not just something vaguely related.
  • Keep clips short. 2–5 seconds per B-roll segment keeps the edit moving. Longer clips need to be earning their place.
  • Use transitions sparingly. Fade works everywhere. Pop and Zoom can be effective. Don’t use a different transition on every clip.

Media Overlay reference

Full feature documentation.

Go from Raw Footage to Finished Video

Let AI Edit place B-roll automatically.
Last modified on April 20, 2026