FREEAPC Editorial tool · Images
Regenerate thumbnails plugin for WordPress, without breaking anything
APC Editorial's Regenerate Thumbnails rebuilds the image sizes your theme uses, after a theme change or a new size. One image, several or the whole library, always from the original and without touching your posts' dates. Free, on your own server.
- Free forever
- Rebuilds from the original
- Keeps your posts' dates
In short
Regenerate Thumbnails rebuilds the image sizes, the thumbnails, that WordPress and your theme use. It rebuilds each size from the uploaded original, keeps the Image Converter's WebP and AVIF copies up to date and never changes your posts' dates.
Use it after changing themes, changing the sizes in Settings › Media or installing something that adds a new size. When your site's sizes change, it notices on its own and marks the whole library to be rebuilt.
- Rebuilds
- The WordPress and theme sizes
- One image
- From the Media Library column
- Several
- Bulk action, one at a time
- All of them
- In the background, up to 20 at a time
- Formats
- JPG, PNG, GIF, WebP and AVIF
- Post dates
- Never change
- Plan
- Free, forever
Image sizes
One photo uploaded, many sizes.
Every image you upload to WordPress becomes several: one for each place your site shows photos.
When it receives a photo, WordPress makes smaller copies of it, called image sizes or thumbnails. That way, the post list shows a light thumbnail, not the whole photo. Since WordPress 5.3, very large photos also get a version scaled down to 2560 pixels on the longest side, and the uploaded file is kept.
Your theme and some plugins register sizes of their own, such as the crop of a blog card or a showcase. The detail that catches many people out: WordPress only creates those sizes at upload time. Older images don't get the sizes a new theme asks for on their own.
| Size | WordPress default | Where it usually shows |
|---|---|---|
| thumbnail | 150 × 150, cropped | Lists, widgets and thumbnails |
| medium | Up to 300 × 300 | Images inside the text |
| medium_large | 768 wide | Medium screens, picked by the browser |
| large | Up to 1024 × 1024 | Large images in a post |
| 1536 · 2048 | Added in WordPress 5.3 | High-resolution screens |
| Theme sizes | Set by the theme | Blog cards, highlights, galleries |
The thumbnail, medium and large dimensions can be changed in Settings › Media. Changed them? Older images only get the new dimensions when you regenerate.
When to regenerate
Changed themes? Time to regenerate.
If your theme asks for a size the image doesn't have, WordPress serves another one instead, often the large photo. The page gets heavier, and the crop may come out different from what the theme planned.
- You changed themes, or the theme changed its sizes in an update.
- You changed the dimensions in Settings › Media.
- You installed a plugin that adds a new size, such as a gallery or a shop.
- A thumbnail went missing or shows cropped in the wrong place.
What it does
From 1 image to the whole library.
A column in the Media Library, a bulk action and a tab of its own to rebuild everything.
One image, in the list
In the Media Library, the APC - Regen. Thumb. column shows how many sizes the image has and a Regenerate button.
Several at once
Tick the images and pick the APC - Regenerate thumbnails bulk action. They are rebuilt one at a time, without straining the server.
The whole library
Regenerate all thumbnails, on the tool's tab, rebuilds everything in the background, up to 20 images at a time, with pauses. You can close the tab.
Only what's missing
Only create missing sizes makes a quick pass, only with the sizes that are missing or have the wrong dimensions. Off, it rebuilds them all.
Optional cleanup
Delete old, unused sizes removes the files the image no longer uses. It comes off, because an old size may still be linked from a post.
Notices a theme change
When your site's sizes change, the whole library shows as pending again, right when it is time to regenerate.
Breaking nothing
Rebuilt from the original, safely.
Regenerating thumbnails looks simple, but it can undo the work of other tools. APC Editorial's was made to live alongside the Image Converter and images created with AI:
- From the original, at full quality: every size comes from the uploaded file, never from an already compressed copy.
- Light copies kept up to date: an image converted to WebP or AVIF gets light copies for its new sizes, in the same format and at the same quality level.
- Never a broken image: if the light copies can't be rebuilt, the image shows the original instead, and the plugin tells you.
- Your posts' dates stay the same: only the resized copies are rebuilt.
- Another image's files are never touched: the optional cleanup only removes the image's own files.
Step by step
Regenerate your thumbnails in 4 steps.
The tool comes off. Once on, it gets a tab of its own and the Media Library column.
-
Turn the tool on
With APC Editorial installed and your jode.io account connected, turn on Regenerate Thumbnails in Global Settings › Add-ons/Tools.
-
Pick the options
In the Options card, decide whether you want Only create missing sizes. Leave the old-size cleanup off if you are not sure.
-
Test with 1 image
In the Media Library, in list view, click Regenerate in the APC - Regen. Thumb. column and check the result.
-
Regenerate everything
On the tool's tab, click Regenerate all thumbnails and you can close the tab. Stop halts it whenever you like.
Want to see each screen? The step by step in the docs shows the tab and the column.
Free and PRO
Regenerate Thumbnails is Free. All of it.
Nothing in this tool is locked behind PRO. It runs on your server and never goes through jode.io.
Forever, with no image limit
- One image, several or the whole library
- Only the missing sizes, or all of them
- Safe with the Image Converter's WebP and AVIF images
- In the background, with the tab closed
What PRO adds
- The featured image created with AI, which is rebuilt safely too
- Planning and writing your articles with AI
- 30 days free to try everything
FAQ
Questions about regenerating thumbnails.
What are thumbnails in WordPress?
They are the smaller copies WordPress makes of every uploaded image: thumbnail, medium, large and the sizes your theme asks for. Your site uses the right copy for each place, instead of loading the whole photo.
When do I need to regenerate thumbnails?
After changing themes, changing the dimensions in Settings › Media or installing a plugin that adds a new size. WordPress only creates sizes at upload, so older images lack the new ones until you regenerate.
Does regenerating change my posts' dates?
No. The plugin only rebuilds the images' resized copies. No post or page changes its date.
Does it work with WebP and AVIF images?
Yes. For an image converted by the Image Converter, it rebuilds the sizes from the original JPG or PNG and then makes the light copies again, in the same format. Images uploaded as GIF, WebP or AVIF are included too, if your hosting can write that format. SVG has no sizes to rebuild.
Are the old sizes deleted?
Only if you turn on Delete old, unused sizes. It comes off, because an old size may still be linked from a post or the page builder, and deleting the file would break that link. Even when on, only the image's own files are removed.
Can I close the tab while it regenerates?
Yes. Regenerate all thumbnails keeps going in the background, up to 20 images at a time, with pauses so the server is never overloaded. An image that fails 3 times is skipped, so it never holds up the others.
Why isn't it inside the post editor?
On purpose. With a post open in the editor, saving the post would write the images' old addresses back, and they would vanish from the page. That is why it lives in the Media Library and on the tool's tab.
Does it need an AI key or a subscription?
No. Regenerate Thumbnails is Free forever and uses your site's own server. You only need to sign in with your jode.io account, which is free.
More add-ons and tools
Works together with these.
Each add-on and each tool turns on and off on its own, in Global Settings › Add-ons/Tools.
APC Editorial
Download it free and use it today.
The Regenerate Thumbnails tool is part of APC Editorial, the plugin to generate articles with AI with editorial planning. Free add-ons and tools stay free forever; PRO ones are unlocked during the 30 free days.