What is B-roll? Meaning, shot types and a tested edit

What does B-roll mean?

Wikipedia defines it as "supplemental or alternative footage intercut with the main shot" (third party, read October 25, 2026). In plain terms: the main footage is a person talking, a voiceover, an interview or an action; B-roll is every other shot you cut to while that goes on.

The B does not stand for a word. It is the second roll. In 16 mm film editing, the same article explains, editors put the odd-numbered shots on one roll and the even-numbered shots on another, joined by black leader so the splices stayed hidden when printed. Roll A held the main footage, roll B the rest. The term later moved into television news and linear video editing, and now means any cutaway or supporting shot.

So "b roll footage", "b roll video", "b roll shots" and "b roll clips" all point at the same thing: footage that is not the main take but supports it. A B-roll shot usually has little or no sound of its own, because the sound you hear while it is on screen belongs to the A-roll.

What is the difference between A-roll and B-roll?

A-roll is what carries the story. B-roll is what illustrates it. The table puts the two side by side with the same example.

Source: the definitions follow Wikipedia (A-roll as the main footage, B-roll as the supplement; read October 25, 2026). The last two rows are our own description of the test edit below. On the proportion, Descript reports that documentary-style videos often use about 60% A-roll to 40% B-roll (third party, read October 25, 2026); that is a description of one style, not a rule you must hit.

Why is B-roll important?

Three reasons come up in every source we read, and we could check one of them ourselves.

First, it shows instead of tells. Descript advises showing what the speaker describes rather than generic stock, and covering voiceovers or off-camera interviews with visuals that support the narration (third party, read October 25, 2026). Second, it hides cuts: Descript lists B-roll as a way to hide jump cuts in interviews and talking-head videos. Third, it controls pace, because every cutaway is a new picture and a new reason to keep watching.

The one we measured is the cut itself. In our test the picture changed three times while the voice did not, so the viewer never loses the thread. Our guide on the jump cut shows what the same cut looks like when nothing covers it.

What are the types of B-roll shots?

Sources slice the list differently (Adorama names five, Descript more than ten). We merged them into five jobs, because the job is what you choose when you plan a shot list. The chart shows where each job sits in a 60 s example plan.

Source: the five jobs are our grouping of the shot types named by Descript, Adorama, Adobe and invideo (all third party, read October 25, 2026); the hold times are the figures those pages report, labelled in the last column; Adorama gives no seconds for these types. The 60 s plan in the chart is our suggestion, not a measurement.

What does a real B-roll edit look like?

To check that the idea survives contact with real footage, we built the smallest honest example: one voiceover as the A-roll, four shots as the B-roll, all made with the free Koldflux browser tools on a real clip we did not make.

The footage is a CC0 clip from Wikimedia Commons, Steam Engine Pulling into Virginia City Station by Thomas Farley (dedicated to the public domain, read October 25, 2026). The voiceover is our own text read by a local synthetic voice, one sentence per shot.

1. Write the A-roll first. We wrote four sentences and generated the voice: 12.885 s, with sentences starting at 0, 3.040, 6.490 and 10.236 s.
2. Choose a shot for each sentence, so the picture shows what the voice says: wide as the train arrives, the wheels and rods, the cab with the crew, the whole train passing.
3. Cut each shot with the free trim tool. We cut 0 to 3, 14.5 to 18, 20 to 23.75 and 30 to 32.65 s, so each shot ends where the next sentence starts.
4. Join the four shots with the free merge tool, in order, in the 16:9 shape.
5. Put the voice on with the free add audio tool, set to replace the original sound. The picture is copied, the voice goes on top.
6. Check it: the picture should change within a blink of each sentence start, and the voice should not move.

The cuts land where the sentences start because we chose the trim ends from the voice timings, not by eye. That is the one habit worth copying from this test: write or record the A-roll first, read its timings, and cut the B-roll to them.

What did we measure in the test edit?

Every file was checked with ffprobe 6.1.1 and ffmpeg 6.1.1. The seams were found by taking the difference between each frame and the one before it and reading its average brightness: inside a shot the number is small, at a cut it jumps.

Source: our own run on October 25, 2026, in headless Chromium against the live trim, merge and add audio tools; the full commands, ffprobe lines and per frame values are in the published log. The median of 5.13 is high because the source was filmed handheld, so every frame moves a little; the three cuts still stand well above it. The 0.092 s tail is something we measured, not something the tool page promises: it says the result is as long as the video, and the container came out 0.092 s longer.

We also ran the trim tool on the original WebM (VP9 with Opus sound) without converting it first. It worked and returned H.264 with AAC, and it kept the clip's own sound. If you want B-roll muted, mute it first with the free mute tool or cut a version without sound.

Free tools:Trim a video by timestampMerge videosAdd audio to a video

How long should B-roll clips be, and how much do I need?

There is no standard. What the sources report: Descript says to capture each clip for at least 3 to 5 s so you have room in the edit, that transition shots run 3 to 5 s, and that slower documentary-style pieces may hold 10 s or more. invideo gives 2 to 4 s for an establishing shot. Adobe suggests counting ten in your head while you film a stationary or moving shot, so you have material to trim (all third party, read October 25, 2026).

Our test used 2.6 to 3.7 s per shot, which sits inside those ranges, because each shot only had to carry one sentence. Our suggestion is to let the sentence decide: the shot should be on screen from the first word of what it illustrates to the end of that thought. For how much, start from the 40% documentary figure only if your video is that style; for a short explainer, plan the shot list around the sentences, not around a percentage.

How do I shoot B-roll with a phone?

We did not test this on a phone and did not film with one, so the points below are advice reported by third parties, not our results. They agree across Adobe, Descript and invideo (read October 25, 2026; invideo through a search summary).

• Make a shot list before you shoot: location, the action you want, the viewpoint and the shot size (Adobe, invideo).
• Vary the size: if the main shot is wide, get medium, close-up and detail shots too (Descript, invideo).
• Hold each shot longer than you think you need, so the editor can trim it (Adobe: count ten; Descript: at least 3 to 5 s).
• Keep camera movement slow and stable; too much movement distracts (Descript).
• Match the conditions of the A-roll where you can, such as the light and the time of day (invideo).
• Shoot the shots that show what the speaker says, not generic scenery (Descript).

Phone footage is often variable frame rate and sometimes HDR, and we did not test what our browser tools do with either. Our test used constant frame rate footage from a camera, and the trim tool kept 29.97 fps through all four trims.

Where can I get free B-roll footage?

Your own footage is the safest, but if you need stock, these are the free routes we checked. Read the licence of the exact file, not only the site.

Source: Creative Commons CC0 1.0 deed, Pexels Licence and Pixabay Content Licence Summary (all official, read October 25, 2026). "Royalty free" and "free" do not mean free of every right: a clear face or a logo in the shot is a separate question from the footage licence. Only the CC0 file in our test was verified at file level (licence read from Commons on October 25, 2026); we did not review individual Pexels or Pixabay clips. This is not legal advice.

If you need B-roll for a Reel, Short or TikTok, cut it in the shape you will publish. The merge tool offers 9:16 (1080x1920), 16:9 (1920x1080) and 1:1 (1080x1080) and pads rather than stretches, so a 16:9 shot in a vertical frame gets bars. Crop it first if you want it to fill the frame.

How do I add B-roll in CapCut, Premiere Pro or DaVinci Resolve?

We did not run any of these applications, so this page gives no menu steps for them. What is the same everywhere: put the A-roll on the base video track, put the B-roll on the track above it, and place each shot where the sentence it illustrates begins. Descript describes the same idea as dropping B-roll over a cut without rebuilding the timeline (third party, read October 25, 2026).

If you do not want an editor at all, the browser route in the test edit above does the job for a short sequence: trim, merge, add the voice. Its limit is that the shots play one after another, so the picture is B-roll only. To show a speaker on camera with B-roll cutting in and out, you need an editor with two video tracks.

What we did not test

We tested one idea on one real clip. Here is what that leaves open.

Our A-roll was a synthetic voiceover, not a person speaking to camera. The technique is the same, but we did not test a talking-head clip, lip sync, or cutting away from a speaker and back.

We tested one source clip, filmed handheld in daylight, and made every shot from it. A real project mixes clips from different cameras, and we did not test mixed frame rates, mixed frame sizes, vertical footage, HDR or a file near the 100 MB limit.

We did not test an editing application or a phone, and we did not run the free sources beyond reading their licence pages and one Commons file.

The coverage chart is our suggestion, built from third-party figures. We did not measure what viewers watch, so we make no claim that more B-roll keeps people watching longer.

Wikipedia, Descript, Adobe, Adorama, invideo, Pexels, Pixabay, Creative Commons, Wikimedia Commons, CapCut, Premiere Pro and DaVinci Resolve are trademarks of their owners; Koldflux is not affiliated with or endorsed by them.

What to do next

Pick the line that matches your situation.

• You have a talking video with visible jump cuts: place a cutaway over each cut, and see our jump cut guide for what an uncovered cut looks like.
• You are planning a shoot: write the shot list from your script first, with one shot per sentence, and use the coverage chart to check you have an establishing, an action and a detail shot.
• You need footage today: check the licence on the exact file, avoid recognizable people and brands, and keep a note of the source URL.
• You have the shots and a voice file: trim, merge and add the audio in the browser, then check the first second after every cut.
• You want the voice for your A-roll: see how to add audio to a video, and our storyboard guide for planning shots before you film.