Image Bulk Optimization

The Optimus WordPress plugin now allows you to bulk optimize your images. Either via the media library, where you can define which images to optimize or, via Tools -> Optimize all images, where you can optimize all images at once. This feature is available since version 1.3.8.

To bulk optimize images via the media library, select all of the images you would like to optimize from the library view and choose Optimize Images from the drop-down. Then click Apply. This will take you to the optimization page where your selected images will be optimized one-by-one.

image bulk optimize media library

The bulk image compression can take quite some time. This is dependent on the amount and size of images. Also the format plays a role. PNG images take much more resources and time than JPEGs. It is important that you do not close or navigate to another site during the optimization process (otherwise it will stop).

image bulk optimize tools

A feature to disable the optimization of images upon upload has also been added since version 1.4. This setting is beneficial for users who don’t want to optimize their images right away. This allows users to upload their images as fast as possible, while giving them the ability to later optimize when they have more time. This setting can be toggled by navigating to Settings > Optimus > Optimize during upload.

Disable Optimize During Upload Feature


  1. Nina Schulz

    Bei mir stoppt diese Funktion immer wieder bei einem bestimmten Bild und läuft dann nicht weiter. Woran könnte das liegen?

    1. KeyCDN

      Kannst du uns dieses Bild senden? Und ganz toll wäre wenn du uns den DB Record (table wp_postmeta) zum Bild auch senden könntest.

      Wir vermuten, dass die Metadaten in der DB nicht stimmen und es darum nicht weiter geht.

      1. Nina Schulz

        Anscheinend gibt es da generell Probleme bei dem Bild. Ich schau mir das mal genauer an und melde mich dann nochmal!

  2. rybred79

    Would be great if when using the bulk optimizer, it gives you the option to optimize only unoptimized images. I will have thousands of images that need to be optimized after uploading, causes uploading to be too slow when optimizing at same time. Currently it has to go through the whole list of images and check if already optimized.

    Otherwise, great plugin. Thanks

  3. SamerKurdi

    I’ve been trying to ‘Bulk Optimize’ for more than a week now, running the bulk optimizer overnight almost every day. The furthest I got was 14558 images out of 14942, which took almost 16 hours. Aside from accidents such as my son closing the laptop, it seems that my internet connection invariably resets at least once during a 24 hour period, causing the process to stop, and refreshing the page sends the optimizatiton process back to square one. This is a serious problem with Optimus and honestly it has caused me more frustration and exasperation than it should. I really want to optimize my entire library; those 400 or so missed images bother me.

    My suggestion to you guys is to have some sort of “continue process” button which the user can use in case the process stops unexpectedly for whatever reason, which would allow the process to pick up where it stopped without having to refresh the web page and redo the whole thing. Please consider this as it would make using this service a lot more pleasant and professional. Thanks.

  4. Joshua Nelson

    Any follow up on the ability to bulk optimize only un-optimized images? This is a key feature that is needed on larger sites.

    I’d also request a bulk optimize via wp-cli option.

  5. Sebastian Brinkmann

    I would like to see a way to launch this bulk optimisation via a Cronjob let’s say one time per day to optimize all new images. After having some problems during optimizing right after the upload (it takes very long time), I use this bulk optimization now.

  6. Heiko Mitschke


    How can I start bulk optimization AGAIN for ALL images? The problem is, that the optimized images were overwritten by unoptimized ones directly via FTP.

    So Optimus shows me, that all images are optimized but they are not…

    Thanks in advance!

    Best regards,

    1. Heiko Mitschke

      I developed a solution for me, so no answer is needed. I disabled the check, whether an image is optimized in the source code and changed the sql-query.

      Alternatively you can use the plugin “Regenerate thumbnails”.

  7. oostenrijker

    Hi, I’m getting a lot of ‘internal errors’ with the bulk optimisation tool.
    It appears to me that most of these (99%) are from images that I screen capture (mac, safari, automatically saved as png).
    Is this a known error that Optimus can’t optimise these kind of images?

      1. oostenrijker

        Yes, I’ve checked that section.
        * All images are still on the server
        * No PHP errors
        * Correct upload directory
        Not all PNGs are giving this ‘internal error’ but a lot of them do. The ones that are optimised are created the same as the ones that give an error. Nothing apparent differences of the images between the optimised and error.

        1. Cody

          Does the issue occur for newly uploaded images? Additionally, if you take an image that returned an internal error and then save it and re-upload it to WordPress, do you continue to see the error for that image?

  8. malina

    all of my images say 0% next to them, meaning the size hasnt changed? It is showing no images available to optimise in the bulk optimiser. I just upgraded as I thought it was because some were too big – over 100k. But it has made no difference. Please advise asap as at the moment this is a waste of money for me.

  9. Matthew Smith

    I’ve been using Optimus for quite a while but have realized that some of my plugins store images in the Media Libary folders but they don’t actually show up in the Media Library from within word press, So I’ve got loads of optimized images.

    It it possible to have a feature like Ewww image optimizer has:

    “Include Media Library Folders

    If your theme or some plugin is generating images in the media library folders, but not registering them properly in the attachment metadata, you can tell EWWW to include the most recent 2 folders in any scans. This applies to Bulk Optimization and Scheduled Optimization. For example, if it is October of 2017, then the plugin will scan wp-content/uploads/2017/09/ and wp-content/uploads/2017/10/ and optimize any images within those folders.”

    It would be really useful to make sure all images are optimised,

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