by junkcoder 4.8 (90 reviews)

AJAX Thumbnail Rebuild

Name: AJAX Thumbnail Rebuild
Rating: 4.8 (90 reviews)
Author: junkcoder

Rebuild your media library one image at a time, without script timeouts - and optimise, replace, or write WebP and AVIF copies of your images.

AJAX Thumbnail Rebuild ranks #1,040 among WordPress.org plugins with 30,000+ active installations, is #117 of 6,327 in the Media category, a 4.8/5 rating from 90 reviews, and was last updated Sep 12, 2026. Data from WordPress.org, refreshed twice daily — see methodology.

Compatible with WP 7.1.1

v2.2.1 Current Version v2.2.1

Updated 6 days ago Last Update on 12 Sep, 2026

Refreshed 17 hours ago Last Refreshed on

#117 of 6,327 in Media Top 5% by installs Downloads -78.6% this week Actively maintained

View on WordPress.org

Rank

#1,040

— No change

Active Installs

30K+

-10.6%

KW Avg Position

50.2

0.6 worse

Downloads

898.7K

+560 today

Support Resolved

50%

— No change

Rating

96%

Review 4.8 out of 5

4.8 (90 reviews)

Next Milestone 40K

Total Progress 30.1%

30K+ 40K+

130

Ranks to Climb

Growth Needed

8,000,000

Active Installs

Pro

Unlock Exact Install Count

See the precise estimated active installs for this plugin, calculated from real-time ranking data.

Exact install estimates within tiers
Track install growth over time
Milestone progress predictions

Upgrade to Pro

Need 6,990 more installs to reach 40K+

Rank Changes

Current #1,040

Change

Best #

Upgrade to Pro

Unlock 30-day and 90-day rank history charts with a Pro subscription.

Upgrade Now

Active Installs Growth

Upgrade to Pro

Active Installs 0,000,000+

Growth +0.0%

Peak 0,000,000

Downloads Growth

Downloads

Growth

Peak

Upgrade to Pro

Unlock 30-day, 90-day, and yearly download history charts with a Pro subscription.

Upgrade Now

Reviews & Ratings

4.8

90 reviews

Overall 96%

83 (92%)

1 (1%)

2 (2%)

0 (0%)

4 (4%)

Support Threads Overview

Resolved

Unresolved

Total Threads

Resolved

Unresolved

50%

Resolution Rate

Security History

Source: WPVulnerability

1 known vulnerability on record · 0 in the last 24 months · checked 1 week ago

Apr 28, 2023

AJAX Thumbnail Rebuild [ajax-thumbnail-rebuild] < 1.14 (closed)

CVE-2022-47604 · Fixed in v1.14

Track This Plugin

Get detailed analytics, keyword tracking, and position alerts delivered to your inbox.

Start Tracking Free

Plugin Details

Version: 2.2.1
Last Updated: Sep 12, 2026
Requires WP: 5.7+
Tested Up To: 7.1.1
PHP Version: 7.4 or higher
Author: junkcoder

Support & Rating

Rating: ★ ★ ★ ★ ★ 4.8
Reviews: 90
Support Threads: 2
Resolved: 50%

Keywords

image Optimize rebuild regenerate thumbnail

Upgrade to Pro

Unlock keyword rankings, search positions, and detailed analytics with a Pro subscription.

Upgrade Now

Similar Plugins

Adminify – White Label, Admin Menu Editor, Login Customizer

6K+ installs

#2,754

Master Addons for Elementor – Elementor Addons, Widgets, Mega Menu Builder, Popup Builder, Widget Builder & Template Kits

30K+ installs

#1,007

Jetpack – WP Security, Backup, Speed, & Growth

3M+ installs

#18

Advanced Custom Fields (ACF®)

2M+ installs

#28

Image Optimization - Compress Images and Convert to WebP or AVIF

Regenerate Thumbnails

1M+ installs

#64

Smush – Image Optimization, Compression, Lazy Load, WebP & CDN

1M+ installs

#65

Imagify Image Optimization: Optimize Images | Compress & Convert to WebP/AVIF

View all Media plugins

TL;DR

AI summary of the plugin's readme

This plugin is for WordPress site owners with large photo libraries who need to regenerate image thumbnails. It rebuilds thumbnails one at a time instead of all at once, avoiding server script timeouts that occur with other bulk-rebuild plugins.

Rebuilds thumbnails without timeouts
Select specific thumbnail sizes
Rebuild only post thumbnails
Requires JavaScript enabled

Frequently Asked Questions

Common questions about AJAX Thumbnail Rebuild

No. A rebuild writes the resized copies again and leaves the file you uploaded as it is. The only setting that touches an original is "Also optimise the full size original" on the Optimising tab, and even then only the lossless programs run on it - never a re-encode.

It stops where it is. The images it had already got through keep their new copies and nothing is left half written, but the run does not carry on in the background - open the screen and start it again.

Look at the Optimising tab: it lists which optimisers are installed on this server. Those re-pack a file rather than re-encode it, which is where the saving is. Where none of them is installed the plugin falls back to PHP's own image library, and since WordPress already wrote those files at that quality there is usually nothing left to win. On such a host, TinyPNG or ShortPixel will do the job over their API.

Turn on background processing, under Optimising. Optimising a file and writing its WebP and AVIF copies both happen while the browser is still waiting for the upload, and neither has to: with this on the upload finishes as soon as the resized copies are written, and the rest is queued. Action Scheduler runs the queue where a plugin provides it - WooCommerce and many others do - and WP-Cron runs it everywhere else. An image is served in its own format for the minute or two before the queue reaches it.

Yes. The copies are extra files written next to your images; the originals stay exactly where they are, a copy that comes out larger than the original is thrown away, and the copies are deleted along with the attachment. Turning the setting back off puts the front end back to serving the originals. AVIF costs several times the processing WebP does, so expect uploads and rebuilds to take longer with it on, and where the server's image library cannot write AVIF the screen says so and the WebP copies go on being served.

Yes, with one line of code. The screen has a single switch per format, but a filter separates the two, so the copies go on being written while the front end serves your originals - which is what you want when a CDN or the server itself hands the copies out: add_filter( 'ajax_thumbnail_rebuild_serve_copies', '__return_false' );

New uploads are converted as they arrive. For the images already in your library, run a rebuild once.

No - a JPEG can only be replaced by a JPEG, a PNG by a PNG. The attachment keeps its name and its address, which is what keeps every post and product already pointing at it working, and that only holds while the file type stays the same.

Only resized files left on disk that no image size on this site refers to any more - what a removed theme or a size you no longer register leaves behind. It shows you the list and what it would free before anything is deleted, and the files your attachments actually use are never among them.

Yes. The screen talks to the site over a REST API of its own, one image at a time, which is what keeps a large library from running into a script timeout.