# How to add B-roll to a video with AI

> Add B-roll with AI by letting a tool place stock or AI clips over your footage, or by making the clips yourself. Tools, steps and a worked example.
- **Author**: Marxx
- **Published**: 2026-11-08
- **Category**: Video editing
- **URL**: https://marxx.ai/library-guides/how-to-add-b-roll-with-ai

---

To add B-roll with AI, let a tool place clips over your footage, or generate the clips yourself. B-roll is the extra footage that covers the main shot while the voice keeps running.

## Tools that add it

| Tool | What it adds | Plan note (checked 3 Nov 2026) |
|---|---|---|
| OpusClip | Stock, AI image and AI video B-roll | Stock: 3 a month on Starter, unlimited on Pro. AI video B-roll on Pro |
| Submagic | Inserts B-roll automatically | Free b-rolls on Starter. Storyblocks b-rolls on Pro |
| Captions (by Mirage) | Automatic scene cuts and B-roll overlays | Listed on its home page |
| Riverside | AI B-roll | See Riverside's pricing page for the plan |
| Vizard | AI B-roll | Listed on its home page |

To make the clips yourself, use a video generator. Premiere Pro (now called Adobe Premiere) lists Generative Extend and generation from the timeline. Runway, VEED and Canva also make clips from a prompt. See the [best AI B-roll generators](/best/best-ai-b-roll-generators) and how to [choose an AI video model](/guides/how-to-choose-an-ai-video-model-for-ads).

We make Marxx. In [Marxx's AI video editor](/features/ai-video-editor) the assistant can add b-roll, and the Generate tab makes video and images with credits. Marxx chat and every supported model are on Match, $29 a month at launch prices (checked 3 Nov 2026).

## Steps

1. Finish the main cut first. B-roll goes over a locked edit, so the timing stays right.
2. Mark every line that names a product, a number or a place. Those lines need a picture.
3. Pick the source. Use stock or your own footage for real things. Use AI for what you cannot film.
4. Drop each clip over its line for two to four seconds. Keep the voice track running under it.
5. Watch every AI clip at full size. Look for wrong labels, odd hands and garbled text. Replace the bad ones.
6. Add captions last, so they sit on top of the B-roll.

## A worked example

Say a 30-second founder clip has 6 lines that need a picture. You cover each for 3 seconds.

- 6 lines x 3 seconds = 18 seconds of B-roll
- 18 / 30 = 60% of the ad
- The founder is on screen for only 12 seconds

If that feels like too much, cover 4 lines instead. That is 12 seconds, or 40% of the ad.

## FAQ

### Is stock or AI B-roll better?

Stock shows real places and things. AI can show what you cannot film, but it can get details wrong, so check each clip.

### Can I use my own footage as B-roll?

Yes. Product shots, packing and screen recordings all work. Place them over the main clip the same way.

### Does AI B-roll cost extra?

Some tools charge for it. OpusClip lists 3 stock B-roll a month on Starter. Check the plan before a big batch.

---
- [More Video editing articles](https://marxx.ai/library-guides/category/video-editing)
- [All articles](https://marxx.ai/library-guides)