The Art of Crafting Thumbnails: Behind the Scenes

Today, we’d like to take you behind the scenes to explore a crucial, yet often overlooked part of our process: the creation of thumbnails. They are the gateway to our videos, and have to meet a few key characteristics: They must give a quick first insight into what the video is about, they have to spark curiosity about the video’s topic, and finally, they must be disruptive and eye-catching no matter where they are shown, regardless of whether that’s the viewer’s home feed or the “Suggested Videos” section.

So, let us take you through the steps we take to create these thumbnails and the thought processes behind each decision: from when the first ideas are being born, until the very end when the final thumbnail illustrations are going live for testing.

How We Create Videos: Recap

In order to have a thumbnail, we first have to create a video, of course! Every video starts with a piece of knowledge that we find so awe-inspiring that we want to share it with as many people as possible. We then dive into thorough research, consult experts, and go through several script revisions to make sure everything is correct and understandable. After that, our illustrators turn the script into detailed sketches and illustrations, which are brought to life by our animators. Once the Voice Over and custom soundtrack have been added, the video is ready to be released. Or is it?

The Thumbnails: The Final Piece of the Puzzle

As soon as the video enters its animation phase, we're kicking off the thumbnail creation process. We start with a brainstorming session. Here, we go through all the existing materials we already have for a video: the script, research notes, scribbles, and illustrations as well as the most current state of animation. The goal is to find visuals that are not only eye-catching, but that they also give you a feeling that you’re already immersed in the story, drawing you in from the very first glance, capturing the core of the video's message with a single image. They have to be interesting, but can sometimes even be done from abstract angles as well, capturing the message of the video with metaphorical visuals. At the end of this process, we also discuss potential title / thumbnail combinations. The thumbnail image, the visual title, and the video title should all work together, giving you pieces of context to the video, and providing a glimpse into the video without giving too much away.

The following image is an example of what a final set of thumbnails looks like, accompanied by the initially planned titles.

Sketching and Feedbacking

Once we have a solid concept for two to three thumbnails, our illustrators create between 10 and 20 sketches. These rough drafts cover many different possible angles and are crucial for visualizing what different ideas might look like in a smaller format. That could mean many things: we might experiment by using different characters, seen from different angles and in different poses doing different activities. We like to use characters that appear in the videos so they are easily connected. But sometimes, we also like to use metaphorical characters that represent the topic of the video or the feelings the video is meant to invoke, like excitement or dread. We then review these sketches, providing feedback and suggestions to refine the visuals, making sure they are both compelling and clear. Many of the sketches are cut right away. Sometimes that’s because they stray too far from the original idea, and sometimes it is because they only serve as a transition to the better sketch.

An example where we used several different approaches for the sketches of the thumbnail for our video “There Are Thousands of Alien Empires in The Milky Way”:

• Sketch 1: A sketch focusing on the alien

This sketch depicts an alien shrouded in mist, looking at the small sailboat on its way through the ocean. It metaphorically, and really nicely captured the concept of humans traveling through the universe in search of aliens, and was later picked as one of the final thumbnail candidates.

• Sketch 2: A sketch focusing on a popular reference

This sketch depicts a human and an alien, where an alien points towards the universe. The concept is based on a popular meme that takes a scene from the animated movie Toy Story, where a fitting caption would be “Aliens, Aliens Everywhere”. This sketch was also picked as one of the candidates for the final set of thumbnails due to its effective, yet simple way of conveying the video’s message.

• Sketch 3: A sketch focusing on the environment

This sketch depicts a sailboat traveling through the universe, surrounded by various celestial objects. This sketch was cut before making it to the final set of thumbnail candidates, mainly because it didn’t fully convey the message behind the video, and because it was visually too busy.

Over the course of two weeks, we meet up once or twice every week to work on the sketches. Illustrators spend up to a couple of hours working on the sketches the first week, and then we meet up once again the week after that to have a fresh look at the first batch of sketches. That way, we can notice if anything is missing or can be improved. It always helps to do creative tasks over the span of a few days, spread out through one or two weeks in order to have a full, unbiased overview of everything we’re working on.

Final Illustrations and Selection

After reviewing the sketches, we identify which route we want to go with for the finalized thumbnails, with the goal of having at least three fully developed and illustrated thumbnails by the end of this process. The illustrators then create the final, polished versions of these selected thumbnails via continuous feedbacking.

Here is an example where you can notice how the thumbnail has been polished as more and more feedback was implemented:

• Step 1: Initial final illustration

This was the first illustration of one of the previously shown sketches done for this video’s thumbnails. During this step, we realized the alien might not be obvious enough so we tried making it stand out by highlighting its eyes.

• Step 2: Refining the alien

While highlighting its eyes definitely made it stand out a bit more, we thought it still wasn’t visible enough, so we tried to fix that in the next step.

• Step 3: Reducing the clouds and adding the glow

By reducing the amount of clouds and adding a glow to the eyes, the alien was definitely easier to notice, but still not as much as we’d like it to be. 

• Step 4: Finalization of the thumbnail

In the last step, we decided to reduce the clouds a lot more so they’re not in the focus of the image. This allowed the alien to be in the focus of the image. Finally, we adjusted the colors to create a visual harmony among all parts of the images. And just like that, the thumbnail was ready to be tested!

Testing and Optimization

Choosing the best thumbnail is not just about looks, it’s also about performance. You might have noticed that thumbnails and video titles change in the hours and days after upload, as we're testing the best thumbnail/title combination. We are able to do that thanks to YouTube’s A/B testing feature, which allows us to present different thumbnails to different viewers to see which one generates the most interest and engagement among our viewers.
During this phase of testing, everyone seeing this video on their feeds will all see one of two or three different thumbnails that we've put into the testing engine. After about an hour, we will receive consolidated data on which thumbnail led to the best performance of the video. Unfortunately, the A/B testing only allows us to test different versions of the thumbnail images, and not the video titles themselves, so we have to manually change them after the video has been uploaded.

This phase is crucial for us and we keep a close eye on the video’s insights to notice even the slightest impact on performance. After a few days, we make a final decision on the thumbnail/title combination based on the data we've accumulated.

To our surprise, we have noticed that the final thumbnail is not always the one that looks the prettiest or even the one we predict might perform the best, but it is always the one that, according to data, sparks the most curiosity.

You might have noticed that we also started updating thumbnails for some of our older videos. With this, we're testing if these videos have additional potential, now that some are also available in 4K.

The Hidden Effort Behind Every Thumbnail

We hope you enjoyed this behind-the-scenes look into the thumbnail creation process! It’s a small but significant part of our mission to make science accessible, engaging, and beautiful for everyone. 

As always: Thank you for being a part of this journey with us! We couldn't do this without your support. 

Much love from all of us at kurzgesagt!