Correction, 2026-10-02: a second pass found more lines we had not measured or sourced. The page said any recording where someone speaks to camera for more than 30 seconds benefits from b-roll, that short-form platforms have trained audiences to expect fast cuts, that b-roll cut to the audio keeps a video watchable at 1x and 1.5x, and that b-roll is often where an AI video budget gets spent first; those lines are now advice or gone. Two example headings still suggested that Kling suits people and products in motion and Seedance suits product b-roll, which we have not tested, so the headings now name the model only. The FAQ called Wan 3.0 at 480p the cheapest way to draft b-roll on 8frame: it is the cheapest of the three models on this page, but Pruna p-video Draft costs less (4 credits for 5 seconds at 720p). The page now also says where the timeline is on 8frame: in the separate Video Editor mode. It also now says that the Montage node's merged file has no sound (the clips' own audio is dropped), so A-roll audio belongs on the Video Editor timeline.
Correction, 2026-10-01: an earlier version called Wan 2.5 the pick for tight budgets (on 8frame it is 102 credits for a 5-second clip at 1080p, more than Wan 3.0 at any resolution) and said Wan, Kling and Seedance each handle certain b-roll subjects well. We have not measured that, so the examples now give prompts and prices only. It also stated that any static shot held over three seconds loses attention, which we cannot source. Its Kling example read as text-to-video; on 8frame Kling v3 animates a start image, which the example now says.
B-roll is supplementary footage that plays over a main subject to support, illustrate, or add visual context to the primary recording.
The primary recording is the A-roll: the interview subject speaking to camera, the podcast host at the mic, the product announcement on stage. B-roll is everything else. It's the close-up of hands on a keyboard while a founder talks about their product. It's the street scene that plays under a documentary voiceover. It's the slow pan across a skincare bottle while the narrator describes the formulation. B-roll doesn't carry the narrative on its own. It makes the main story easier to follow and more engaging to watch.
How b-roll works
Editors cut to b-roll for two reasons: to illustrate what the speaker is describing, and to cover cuts in the A-roll that would otherwise look jarring. When a speaker says "we tested it in three countries," a cut to footage of a map, a factory floor, or a field team doing their work makes the claim concrete. Without that cut, the viewer is just watching a talking head. With it, the narrative has visual evidence.
In the edit timeline, b-roll sits on a track above the A-roll. The A-roll audio keeps playing. The b-roll video covers the A-roll video. That's the basic mechanic. Duration, pacing, and what the b-roll actually shows are the craft decisions that determine whether it adds clarity or just fills time. On 8frame, the timeline lives in the separate Video Editor mode, which has video, text, caption and sound layers; on the canvas, the Montage node joins 2 to 10 clips in sequence for 10 credits, but the merged file has no sound, so the A-roll audio goes on the Video Editor timeline.
For AI video, b-roll is a natural place to start. A talking-head A-roll is cheap to record. B-roll that matches the mood, color grade, and context of the primary footage has traditionally needed a crew, locations, and post work. Generating it turns that into a per-clip price in credits, which the examples below spell out.
When you use b-roll
Interviews and podcasts. Long stretches of a subject speaking to camera are where b-roll coverage helps most. It gives editors room to cut without creating visible jump cuts, and it turns a static shot into a visually varied sequence.
Documentary and explainer content. Voiceover-driven content with no live action almost entirely depends on b-roll. The footage is the medium. There's no A-roll face to cut back to, so every second of screen time needs to earn its place.
Product ads. A 15- or 30-second ad often opens with a problem or lifestyle scene before showing the product. That opening scene is b-roll relative to the product's hero shot. It sets context, mood, and aspiration before the product appears. Lifestyle b-roll in the middle of a product video keeps the brand on screen without a hard sell.
Social content and reels. Short-form edits tend to move fast, so editors keep static shots short. Cutting b-roll on the beat of the audio is a simple way to hold that pace.
Examples on 8frame
Wan 3.0: cheap drafts. The Wan tool starts on Wan 3.0: a 5-second clip is 95 credits at 1080p, 48 at 720p and 24 at 480p, so you can draft at low resolution and re-run the keepers. Try a prompt like "wide shot, golden hour, people walking through a city market, shallow depth of field, warm grade, handheld feel" and check crowds and faces before you use the take. Wan 2.5 is still in the picker at 1080p only (102 credits for 5 seconds). See Wan 2.5 prompts for b-roll for prompts organized by scene type.
Kling v3: animate a still. Kling v3 Standard is 86 credits for 5 seconds with sound or 57 with sound off; b-roll usually sits under someone else's audio, so silent is often what you want. Kling v3 animates a start image, so begin with a still of the scene, then prompt the motion: "woman opening a skincare bottle, natural window light, slow motion, shallow focus on product label." For text-only prompts, Kling 2.6 Pro is 95 credits for 5 seconds with sound or 47 without. Check hands and label text before the clip goes into an ad.
Seedance 2.5: a product shot. Seedance 2.5 at 720p is 157 credits for 5 seconds (70 at 480p); Seedance tops out at 720p. For a packaged good, try "hero product rotating on marble surface, dramatic side lighting, smoke wisps, cinematic." Set duration and resolution in the node rather than in the prompt. See the best AI video generator 2026 comparison for more on the video models 8frame hosts.
FAQ
What is the cheapest way to draft b-roll on 8frame? Of the three models above, Wan 3.0 at 480p: 24 credits for 5 seconds. 8frame also hosts cheaper video models, such as Pruna p-video Draft at 4 credits for 5 seconds at 720p; we have not compared their output, so run a test take on your own prompt first. Re-run the takes you keep at a higher resolution.
Should b-roll clips have sound? Usually not, since the A-roll or voiceover carries the audio. On Kling v3, turning sound off drops a 5-second clip from 86 to 57 credits.
Related concepts
- What Is Text-to-Video AI? explains the generation process behind every AI b-roll clip.
- What Is a Hero Shot? covers the primary footage that b-roll is built to support.
Sources
- Wan 3.0, Wan 2.5, Kling v3, Kling 2.6 Pro, Seedance and Pruna p-video Draft prices and limits (calculateWan3Cost, calculateWanCost, calculateKlingV3Cost, calculateKling26Cost, calculateSeedance2Cost, calculatePrunaVideoCost): 8frame tool registry, read 2026-10-02
- Video Editor mode (a timeline with video, text, caption and sound layers) and the Montage node (2 to 10 clips, 10 credits a run): 8frame front-end and tool registry, read 2026-10-02; Montage output has no audio track (the render worker's ffmpeg call drops audio): 8frame back end, origin/main, read 2026-10-02
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