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- 97% of YouTubers make these mistakes with their thumbnails
97% of YouTubers make these mistakes with their thumbnails
(here's how to fix them)
Your thumbnail is the most important part of your YouTube video.
Why?
Because if you can't get the viewer click, it doesn't matter how good your video is. The viewer won't be watching it.
Yet, most YouTubers treat thumbnails as an afterthought.
They pour hours into scripting, filming, and editing, only to create a last-minute thumbnail and hope for the best.
Big mistake.
When your thumbnail doesn’t work, your channel doesn’t grow.
And when your channel doesn’t grow, frustration creeps in.
Views stay low.
Motivation fades.
Eventually, you start questioning if YouTube is even worth it.
But here’s the good news: you can fix this.
Today, I’m going to break down the 3 biggest thumbnail mistakes I see and how to avoid them.
Let's do this.
1. Curiosity gap
Creating a "curiosity gap" is a technique many of the top YouTubers use to make you click. You just don't realise it.
So, what is a "curiosity gap?"

It's the space between what the viewers understand from your thumbnail and what they want to know.
The key to a strong curiosity gap is balance:
Provide enough context to understand the video, withhold the crucial information that can only be found by clicking.
What is the curiosity gap of this thumbnail?

Let's look at this thumbnail by Ali Abdaal.
How does he create a curiosity gap?
The viewer understands it's a video about how to stop wasting your life. This is something many viewers want to do.
In the thumbnail, we see how he goes from a person that spends too much time on their phone (many viewers will relate to) to a person that is productive (many viewers aspire to be).
The information that is withheld is what the 5 things are that transformed him from the person in the before, to the person in the after. This is the information that the viewer wants to know the most.
To find out this information, you have to click on the video.
A perfect curiosity gap.
How to create a curiosity gap
The thumbnails with the best curiosity gaps use one of these 6 methods:

Moment thumbnails - Capturing a glimpse of a moment right before a powerful reaction
Result thumbnails - Showing the end result of something and making the viewer ask: "how did they do it?"
Transformation thumbnails - The desire to know the story and process from point A to point B.
Challenging expectations thumbnails - Creating cognitive dissonance in the viewer's mind urging them to click to resolve this discomfort
Story thumbnails - Showing a point of tension that hooks viewers sets up the story
Novelty thumbnails - The desire to watch something we've never seen before
The best way to learn how to improve the curiosity gap with your thumbnails is by analysing top YouTubers.
So, here's what I want you to do:
Create a private playlist on your YouTube account titled "thumbnails"
Everyday, add thumbnails that intrigued you or made you click
Spend 15 mins/day breaking down whey intrigued you and what the curiosity gap is
Take those learnings into your next video
The more you do this, the better you’ll become.
2. Too cluttered
It takes our brains <1 second to decide whether a thumbnail is work clicking on.
If it's too cluttered, our brain is overloaded with information, making it harder to process quickly.
If it takes too long to process, the viewer will lose interest and scroll past.
Here's why your thumbnail is too cluttered:
Too many elements
The average person can only hold 3-5 pieces of information in their short-term memory at a time (according to Nelson Cowan).
Any more than that increases the cognitive load, making the information harder to process.
Which is why you should follow the "3 Element Rule" with your thumbnails.
Have 3 elements that grab the viewer's attention and provide context for the video.
Fewer elements also means each one carries more weight.
This makes the emotions, expressions, and curiosity gap in a thumbnail stand out more powerfully.
Let's look at an example:

Too many colours
Our brains are able to process colour quickly, but too many competing colours creates visual noise.
Stick to 4 main colours to keep the design simple and easy to process.
You should also be using colours that create a strong contrast. This makes the elements in your thumbnail stand out more.
I use the Canva Colour Wheel to find complementary, triadic, and tetradic colours, which are colours that create high contrast when put next to each other.

Too much text
If you want to add text to your thumbnail, you should use no more than 6 words.
Again, any more and it becomes too difficult to process quickly.
You want to be using language that is simple and use a font that is clear and bold.
Please stop using those fancy, cursive fonts.
You should also be strategic with the phrases that you use. You want to create open loops in the viewer's mind, or create cognitive dissonance that entices them to click.
Here is an example:

You can read my article on The mind game YouTubers play to make you click to learn more about this.
3. Too boring/too unbelievable
There is this idea that the more unbelievable a thumbnail is, the better it will perform.
This is incorrect.
Our brains have a built-in filter for realism.
If a thumbnail looks too exaggerated or fake, they won't click as their brain dismisses it as untrustworthy.
Even worse, if they do click and you don't deliver on what the thumbnail showed, they will immediately lose trust and won't watch any of your future videos.
This is why everyone HATES clickbait.
An unrealistic thumbnail can also create confusion, leading to hesitation rather than action.
This is the last thing we want when they have <1 second to make a decision.
On the flip side, it's pretty obvious why viewers won't click if a thumbnail is boring.
You haven't built intrigue in their mind to want to find out more.
Your goal is to find the balance. It needs to be absurd but believable.
Ask yourself:
Why should the viewer click?
Is there a curiosity gap?
Am I portraying the video in its true light?

One other thing:
I'm currently running free, 1-1 YouTube consultation calls.
I will:
Review your channel
Analyse your latest videos
Give actionable strategies to improve
Answer any YouTube growth questions you have
If you're interested, you can book your free call here.
Thank you for reading.
See you next Sunday,
Rory "thumbnail-obsessed" Marles