This is a feature of the Feast Plugin
Thumbnail sizes that are registered by the theme disappear when changing themes, which leads to irregular image sizes and issues when changing themes (and sometimes updates).
To fix this, we've registered some new image sizes in the Feast Plugin that stay persistent even when changing themes, making it so that
Additionally, these thumbnails more accurately reflect the content width on both mobile and desktop, which reduces the amount of bandwidth used by your server, saving you money.
This will make running your blog easier, combined with our new recommendation to upload at:
All featured images should be uploaded at 1200x1200 px.
The Feast Plugin contains more modern thumbnail sizes for food blogs. This brings all themes in line with what we now know are best practices, and offers a consistent thumbnail size for all themes.
As with all major updates, perform this on a staging site first and perform a thorough check. Start with your top 10 posts, then your categories, then your homepage.
- Modern thumbnails
- Why "modern" thumbnails?
- 1. Add the basic modern thumbnails
- 2. Add your preferred thumbnail orientation
- 3. Regenerate thumbnails
- 4. Update your widgets
- Featured image size
- Best practice: remove theme thumbnails
- Breaking change
- In-content post images
- Block editor bug
- Image re-optimization
- 💬 Comments
Now that the themes have been consolidated to a 720px desktop and 360px mobile width, our thumbnails should reflect these sizes. Balancing disk space and image quality, we can safely move to 3 primary thumbnail widths:
- 720px (full-width desktop content)
- 360px (half-width desktop content, full-width mobile content)
- 180px (quarter-width desktop content, half-width mobile content)
The reason we want 180px is that we display all posts on the homepage and category pages at half-width mobile by default.
There are also 3 possible thumbnail orientations: square, landscape, portrait. We've matched the image dimensions Google's Featured Image specifications (+ recipe card) with a 3:4 ratio.
For more information, see how thumbnails work.
This means the possible sizes we're dealing with are:
- 1:1 (square) - 720x720, 360x360, 180x180
- 3:4 (portrait) - 720x960, 360x480, 180x240
- 4:3 (landscape) - 720x540, 360x270, 180x135
Note: this assumes that you're using the recommended content+sidebar layout for desktop. Using content areas without a sidebar on desktop will require registering custom image sizes.
Why "modern" thumbnails?
- The theme's thumbnail sizes are no longer optimal for the layouts being used
- Removes image size issues when changing themes
- Setting these thumbnails using the plugin allows us to update the sizes down the road if necessary (for example, supporting the sizes attribute)
Google Discover currently requires 1200px width (minimum) images, and the themes were not designed with this requirement in mind. The modern thumbnails are.
We believe that article and recipe schema will eventually require this size as well.
1. Add the basic modern thumbnails
Go into the Feast Plugin and add the two basic modern thumbnail sizes: square thumbnails, and in-post thumbnail sizes.
There's also the in-post thumbnails, which we recommend enabling.
The in-content thumbnail sizes do not crop the image, instead they simply resize the image to match the specified width (720, 360) regardless of the height - the images remain proportional.
2. Add your preferred thumbnail orientation
The themes were built to use portrait (vertical) images, and we expect that most people will continue with this option.
However, we've also added landscape (horizontal) images as an option for anyone that wants to try a different layout.
If you have lots of disk space on your server, you can enable both portrait and landscape images.
3. Regenerate thumbnails
Go into the Regenerate Thumbnails Plugin at Admin -> Tools -> Regenerate Thumbnails and regenerate thumbnails - select the option to remove all unregistered thumbnail sizes.
Note: Shortpixel throws a warning about the Regenerate Thumbnails plugin, but we've never seen any conflicts/issues. Do not use their Regenerate Thumbnails Advanced plugin they recommend. It lacks some configuration options.
Note #2: If removing theme thumbnails (see below), you do not want to "Delete thumbnail files for unregistered sizes [...]" unless you plan on replacing all your images previously inserted as thumbnails.
4. Update your widgets
Finally, you'll need to update your homepage widgets (if using the original theme homepage).
You'll also want to update the archive settings to use the new thumbnails in Customize > Theme Settings > Archive Grid:
Featured image size
All featured images should be uploaded at 1200x1200 pixels, as a square image. We'd recommend using this same image for your recipe card, as well.
Featured images are not designed to be displayed in the post. You can use the same image in the post if you'd like, even at different dimensions.
Best practice: remove theme thumbnails
Each theme has different sizes, due to different periods in which they were designed and developed. They're not all optimal, and should all be removed after the modern thumbnails in the plugin are added. See note about "Breaking changes" below.
In order to do this, go to the Feast Plugin and check the box to remove theme thumbnails:
Note: this will only work on themes from Feast Design Co. Other themes will require you to edit the functions.php file, or create a custom function in the Code Snippets plugin to remove the theme's registered thumbnails.
If you've inserted your post images as thumbnails, they'll have the thumbnail size appended to the filename, and these images will break if you select "Delete thumbnail files for old unregistered sizes [...]" after removing theme thumbnails.
Another option is to simply leave the old thumbnail sizes that were registered in the themes. This doesn't cause any major problems aside from filling up your disk space with images that you won't be using any longer.
In-content post images
See the modern post image sizes page.
Block editor bug
On posts not originally written in the block editor, it will show the image size as "thumbnail" (150x150px) on the right-hand sidebar even when it isn't a thumbnail.
This is a purely visual error and not actually correct.
You can just change this to "Full Size", or ignore it. There's no need to go into each post and update old posts just for this.
If you are editing posts or inserting new images, make sure to select "Full Size".
Q: can we change WordPress to automatically use "Full Size" instead of "Large"?
At this time, no.
We've revived a request to make this editable: https://github.com/WordPress/gutenberg/issues/8663
This is especially frustrating, because WordPress does have a setting built in to it for you to specify the defaults:
Whoever developed the "image" block in the block editor simply decided to break this functionality.
If you use the Shortpixel plugin for image optimization, it will automatically re-optimize the new thumbnails you generate. This means it will consume credits for each new thumbnail size you enable. The more images you have, the more thumbnails you'll need to pay to resize.
Consider this being a victim of your own success.
In Shortpixel, Lossy provides the highest image compression, and should be used if you don't see large image quality issues.
Glossy would be the next-best, with Lossless being almost useless.
Make sure to keep a backup of your original images.
We also recommend removing EXIF (this is unnecessary data about the camera), and resize images to maximum 1200px wide, 2000px high. Thanks to Andrew @ Nerdpress for this recommendation.
We do not recommend or support the Smush plugin, or Imagify.
We've implemented this on a number of sites without any issues, but can't be sure we're compliant with every possible configuration. We highly recommend doing this on a staging site first, or having daily backups through your host that you can easily restore if something goes wrong.
You can deactivate the Shortpixel plugin while doing this if you don't want to use optimization credits.