Summary

The article explains how Medium determines the featured image for posts and how to set a custom focal point for these images.

Abstract

The article delves into the mechanics of how Medium handles featured images, revealing that images wider than 700px are scaled down to that width, and featured images are cropped to a 112x112px square. It also uncovers a method for setting a custom focal point by holding the "Alt" or "Option" key and clicking on the desired area of the image within the post editor. This discovery contradicts the initial assumption that Medium always crops images from the center and provides a valuable trick for content creators to control the appearance of their posts on the platform.

Opinions

The author initially hypothesized that Medium crops featured images from the center, which was confirmed for non-square images.
The author was surprised to find that Medium scales down square images without cropping for the featured image.
When dealing with tall images, the author observed that Medium scales the width to 112px and then crops to a 112px height from the vertical center.
The author encountered inconsistencies in cropping when comparing their own featured image crops with those of Medium Creators, leading to the discovery of the focal point setting feature.
The author suggests that any image size is acceptable for Medium posts, but recommends ensuring a part of the image looks good when cropped to a square for optimal featured image appearance.
The author expresses satisfaction with the learning outcomes of their experiment and the value of the discovered trick for Medium users.

How Featured Images Work on Medium & How to Set the ‘Focal Point’

I was curious how Medium “decides” to crop featured images. So I did some testing. I also learned a super valuable trick on how to set the focal point of your featured image.

First some basics

The content area of a Medium post is 700px wide (px is pixels).

That means any image wider than 700px will get scaled to 700px width and the height will adjust accordingly.

The Medium featured image is a 112x112px square.

What we want to know is how and why that featured image square looks the way it does.

The Experiment

Let’s start with this image below. Originally it’s 1200x600px. Medium scales it to a width of 700px and the height adjusts accordingly to 350px (.58 scale of original image).

My first hypothesis was that Medium will default to cropping an image in the center. So if we draw a square in the center of the above image, we should be able to guess what our featured image will be.

Here’s my guess:

And we’re right! Below is how the above image gets scaled and cropped for the featured image.

What about a perfectly square image like this one?

This image is originally 1200x1200px. When I put it into this Medium post, it scales to 700x700px.

Will Medium crop a square in the center of the image? Or will it scale down this square to the 112px size?

It scales it. The featured image isn’t cropped at all since the original image was a perfect square. It just scaled it down to a width of 112px.

What if we have an image that is taller than it is wider?

The image below is 1200x1800px. I can’t imagine anyone putting an image this size in their posts, but this is for science!

bird’s eye view of a boat garage on the water

Here’s the result of the above image when it’s cropped for the featured image.

It appears the image is first scaled to a width of 112px and then it’s cropped at a height of 112px at the vertical center.

Featured images are first scaled to a width of 112px then they are center cropped at 112px height.

I thought my job was done, but then I came across something odd…

I saw this post below from Medium Creators:

Here’s the image from the post:

It seemed to me the crop of this image was off-set to the left and not centered like we discovered in the tests above.

I decided to test the image from this Medium Creators post and see what happens when I set it as a featured image in my own post.

When I featured it myself, it looks different than the Medium Creators’ post:

What!? They are different crops. Mine is centered like we would expect from our tests. What gives??

I tested this with another random post. Maybe the image I saved got weirdly resized or something.

I tried it with this post from Lipika. (The image credit is “Photo by KoolShooters (pexels)”).

Original:

My version:

They are the same crop! What gives again!

Well I figured Medium probably has a special permission they’ve granted themselves where they can edit how a featured image is cropped.

But before I gave up I decided I should google “medium featured images” and see if anyone has shared a secret about featured images.

Lo and behold on a Medium support page (whodathunk) I found that you can set the focal point for a featured image.

How to set the focal point for a featured image:

While editing your post, hold the “Alt” or “option” key
Click an image in your post where you want the “focal point” to be
A green circle will appear in that location

I tested this of course:

It worked! However, note that when you go to settings to “Change your featured image” the preview will still be the original focal point of the images.

When you publish and view it in the post preview, it works!

Conclusion

Well I learned a lot today. I hope you did too.

Images are first scaled to a width of 112px and then by default they are cropped to a height of 112px at the vertical center
If you want to customize the “focal point” of your featured image you can do so by holding “alt” and clicking on the image.
Any size image is fine for a Medium post, but to make the most of the featured image, make sure there is a part of your image that looks good if cropped to a square.