How to use A/B testing to improve your video

What’s A/B testing for video?

A/B testing for video is the process of creating two or more versions of the same video and comparing their performance to see which one works better. Instead of assuming, you test two versions, like different intros, video lengths, content, or thumbnails, and use real viewer data to decide which video drives more engagement, clicks, or conversions.

An A/B test to improve your video helps you understand what resonates with your target audience by looking at analytics. By showing different versions to separate audience segments, you can pinpoint which elements catch attention, keep people watching, and encourage further action.

Now you might wonder, how is this different from the A/B testing you might already know from email marketing - subject lines or web page copy? We’ve got you. It’s because:

• Video is multi-layered: With web copy or email, you’re usually testing one element; a headline, a button color, a CTA. In a video, there are dozens of moving parts: the opening frame, captions, music, visuals, thumbnails, etc. Each element can completely shift how your audience engages.
• Video behavior is emotional: People just skim emails and web pages, but they feel videos. The tone of voice, the rhythm, even a tiny pause, can change whether someone keeps watching or scrolls away. That makes multivariate testing not just about words, but about the full sensory experience.
• Metrics go deeper: For email, it’s usually clicks and open rates. For the web, it’s conversion and bounce rates. But with video, you’ve got a richer canvas: watch time, completion rate, drop-off points, replay rates, shares, and much more.

So, A/B testing to improve your video isn’t just another marketing strategy experiment - it’s your way to figure out what makes viewers stop, watch, and act.

Why A/B testing for video matters?

The video A/B testing process gives you clear evidence of what works (and more importantly, what doesn’t). There’s no need to guess if your viewers prefer a fast-cut hook, a dramatic intro, or vibrant visuals. All you need to do is run your test with multiple versions and measure performance, so you can see which one performs better. After that, just let the data guide your next move.

Our clients agree that A/B testing for video isn’t just some strategy to use once in a while - it’s a way of avoiding wasting resources and to optimize with purpose. If each tiny tweak (be it the title, thumbnail, or pacing) can lead to a big change in watch time, clicks, and conversions, then knowing which video version did best is a true power move and a smart investment.

For example, YouTube creators A/B tested swapping just the thumbnail (while keeping the same video title) and boosted CTR by about 37% to over 100% in a short-period test. These are the kind of jumps that push videos from being meh to must-watch. This test proves that even tiny optimization of what people see before they click can make a big ripple effect in views, reach, and ultimately, video performance. Imagine what swapping other elements could do?

That’s why A/B testing matters so much for video! Every small improvement compounds and could turn a video into a high-performing asset that actually grabs attention, keeps viewers engaged, and drives further action.

What can you test in your videos?

When it comes to running an A/B test to improve your video, the possibilities go way beyond thumbnails. We know - we tested everything ourselves. Every element you can think of - visual, audio, structural - can influence how your audience reacts. So, here are some of the most impactful elements to experiment with. 

Take notes and keep in mind not to test everything at once. One element at a time!

Thumbnails

We’ve mentioned them already, but thumbnails are the first impression. This is the only element that shows up before the actual video itself. A face with a strong emotion versus a clean product shot can determine whether people click or not. So don’t be afraid to test colors, text overlays, close-ups, or even subtle design tweaks to see which one sparks curiosity in your viewers.

Still wondering if a different thumbnail is worth it? Well, HBO Max is planning to implement A/B testing for their streaming content and starting with, you’ve guessed it, thumbnails. The rollout begins with popular titles and will later expand to personalized thumbnails tailored for individual users. This move shows us how even major streaming platforms now view thumbnails as a critical part of higher engagement scores. Heck, Netflix did it nine years ago!

Titles and text

The title of your video is there to set expectations. With this test, you should wonder: does a question title perform better than a bold claim (Can this app save you time? vs. This app will change your workflow). You should even test capitalization, word count or urgency - all this can significantly impact your click-through rates.

Images in video

The visuals you layer into your video can completely change how your message lands. From our experience, even small swaps like replacing generic stock photos with UGC can boost trust and keep viewers watching longer. The right imagery doesn’t just make your video easy on the eyes - it shapes the story, sets the tone, and makes your content stick.

Footage

The footage you choose can change the entire tone of your video. Test versions that swap in different b-roll, live action vs. animation, or alternative camera angles. 

Background music

Music is what sets the mood. For example, Warner Bros. released multiple trailers for Suicide Squad as part of their marketing efforts. The first was dark and moody, which set expectations for a bold, serious film. Later on, they dropped another version with Queen’s Bohemian Rhapsody blasting in the background, and the overall vibe suddenly shifted to chaotic fun and irreverence.

The conclusion: Same movie, same footage, but the music reframed the film as a wild, energetic ride rather than a grim superhero drama.

So running an A/B test on background tracks can show us if viewers want energy or calm when they engage with your content. Sometimes, even an original score can do wonders, also known as a jingle. Think Coca Cola’s Hilltop ad from 1971, famous for it’s chart-toping I’d Like to Buy the World a Coke song. But how to know which music to use? A/B test it!

Voiceover or sounds

Does your video have narration? Think David Attenborough (BBC’s Planet Earth) - the voice you instantly connect to documentaries and nature. Calm, warm, and reassuring. Or Orson Welles’s famous radio broadcast of War of the Worlds from 1938. that caused panic in millions, which directly proves the power of narration.

You should wonder if your video has clear narration, or if a different tone would work better? Or even no narration at all? You can test all kinds of voiceovers, accents, or even sound effects, which can ultimately impact your overall video performance. 

Colours of elements

If music occupies your ears, then color draws your eyes and, once again, works with your senses to create a mood. A bold red or yellow overlay can spark urgency, while soft blues or pastels feel calm and refined. Just look at Netflix’s fiery red, which grabs attention compared to Apple’s sleek grey-and-white minimalism. Testing colour schemes in text, graphics, and buttons shows you what pops off the screen and pulls your viewers in.

Video length

Attention spans are short nowadays on all social media platforms, but not all content needs to be under 30 seconds. Test a 30-second highlight version against a 90-second deep dive. You may find out that your audience prefers a quick video or that they’ll happily stick around for more detail if the hook is strong enough. It could be a very handy part of your social media strategy.

Hooks

We know this from personal experience - the first 5–10 seconds are everything. Does your video open with a question, a bold claim, or a striking visual? Testing different hooks can show you what keeps people from scrolling away in those critical opening moments.

Captions & subtitles

Accessibility isn’t just good, it’s very powerful. Captions can boost watch time, especially on mobile where many people watch videos with the sound off. Here, you can A/B test: 

• Caption styles (burned-in or platform auto-generated)
• Fonts
• Caption timing (smoother vs. faster-paced)

Visual style 

The way your graphics move and look can change the entire feel of your video. Static text overlays are clean and minimal, while kinetic typography adds more energy and motion. Flat design keeps things modern and simple, and 3D graphics bring depth. Think of Marvel’s bold, cinematic 3D title cards alongside Google’s playful, flat visuals. You recognize both instantly, but they set completely different tones.

End screens & cards

For all of you YouTube folks, don’t ignore your end screens. Testing whether you suggest another video or send viewers to an external website can completely shift their journey. Let’s take MrBeast as an example, with 437 million subscribers on YouTube. He frequently links to other videos, because he know that it’s smart to keep viewers in a binge loop. Why? Because it drives higher retention and more channel growth. 

Even YouTube shared that end screens and cards increase retention and directly influence overall watch sessions, so testing which options hold your audience longest is worth every second. Plus, you can track end-screen element click-rate in YouTube Studio and find out what works best.

Call-to-action (CTA)

A good call to action is like a bridge between a viewer watching and a viewer acting, so it’s only logical that when and how you deliver will hugely impact conversions. A/B testing can tell you whether a mid-video Subscribe now! prompt outperforms a closing CTA, or if an on-screen button gets more clicks than a verbally spoken line.

Big YouTube creators often place CTAs right before viewers tend to drop off (which you can spot if you watch your metrics) to keep engagement high. Sometimes a soft nudge works better (Check out the next video) than a hard sell (Buy now), and testing will show you which tone your audience actually responds to and takes that action.

Step-by-step guide on how to run video A/B tests

Okay, we know there are a lot of elements you can test, but running an A/B test to improve your video doesn’t have to be so overwhelming. From our extensive research and experience, here’s a clear roadmap you can follow to avoid headaches when conducting these tests.

Define your goals

Every good test starts with a clear purpose - your testing goals. Before you begin testing elements, you should lock in a single, measurable outcome. This is what will tell you if your experiment actually worked. Here are some common goals and metrics to look at:

• Click-through rate (CTR) - This is perfect for thumbnail or title tests. YouTube says the average CTR is 2–10%, so aim to beat that range and you’re good.
• Audience retention - This is useful when testing video length or hooks. Many creators say they see a sharp drop-off in the first 30 seconds, so if you improve this number, you’ve got yourself a big win.
• Conversions or click-outs - These are considered best for CTA tests. You can track clicks to sign-ups, landing pages, or purchases, depending on your funnel.
• Engagement (likes, comments, shares) - This is good for testing multiple elements like music, tone, or style, where the goal is to spark stronger reactions with your audience.

Identify what element you are testing

Now that you have your goal, we should mention once again - don’t change every element at once. Focus on one variable like the thumbnail, background music, or video length. And if you swap too many elements, even two, you’ll never know which change actually made the difference in your video. Rather, try to focus on one element and one variable at a time to get clear results.

Create video variations 

Once you know what you’re testing, it’s time to create two versions. This could be as simple as swapping the thumbnail or as involved as re-editing the entire intro. But to do so, you’ll definitely need a tool like Plainly Videos. Plainly supports automated video versioning, which means you can quickly generate multiple variations without hours of manual editing. The key here is to keep everything identical except for that one element you’re testing, so your results stay clean and reliable and you can easily determine which version performs better.,

Split your audience and launch campaign

The fourth step is the fun part - you’re showing your variations to the world. The goal here is to split your audience evenly, in sample sizes, so each version gets a fair shot. You can do this with platforms that support A/B testing, like:

• YouTube Experiments - which is great for testing thumbnails and titles.
• Google Ads - lets you run controlled video ad split tests.
• Facebook Ads Manager - perfect for testing creative variations with targeted audiences.
• TikTok Ads Manager - useful for short-form video tests with a younger demographic.

By using these tools, you make sure your data stays unbiased, so you’ll know which video version actually performs better.

Analyse the results

When your test has gathered enough data, it’s time to dig into the numbers of your video marketing. Look at metrics that match your goal - CTR for thumbnails, watch time for hooks, or conversions for CTAs. But, how long should you wait for your A/B test to gather enough data? How much is enough time?

• YouTube’s recommendation is to run thumbnail tests for а few days or up to two weeks for solid results. 
• From what we’ve seen with our clients, you should aim for at least 1,000+ impressions per variation as a minimum baseline, and larger channels should push for 5,000+ impressions to reach significant results to look at.
• When it comes to ads (Google, Facebook, TikTok), many marketers have seen the best results by running tests until each version has at least 100 conversions or meaningful clicks, which ultimately depends on your campaign goal.

Ready to A/B test your videos for better numbers?

By now, you’ve seen how powerful A/B testing can be for video. From tweaking thumbnails and hooks to experimenting with music, colours, and CTAs - every element gives you a chance to lift your click-throughs, retention, and conversions, but with the right approach and strategy.

Again, here’s what we went over together:

• What A/B testing for video is and why it matters
• Which elements you can test - from background music to colors
• Real-world examples showing how small tweaks change overall performance
• A step-by-step guide for running your own video A/B test
• Tools and tips to make testing faster and more effective

The next move is on you. Don’t just guess which video will perform better - back it with solid proof and run the test. And then a new test, again and again. With the help of tools like Plainly, you can create automated variations in minutes, so you don’t have to spend so much time on different versions of the same video. Once you have that, it’s easy to launch split tests across platforms and let the data show you what really works and what doesn’t.

So, are you ready to turn small element tweaks into big wins? Start your 14-day free trial with Plainly, book a demo, see it in action, and start running smarter video A/B tests that bring you the numbers you’re chasing today!