BytCrush

Getting started

BytCrush is set up with recommended defaults as soon as it's activated. The steps below take a few minutes, plus however long your library takes to optimize.

1. Install and activate

  1. In WordPress, go to Plugins → Add New, search for BytCrush, then click Install and Activate. If you have the zip file, upload it under Plugins → Add New → Upload Plugin instead.
  2. You may see a Freemius opt-in screen. Opting in is optional; you can skip it. See Privacy and data.
  3. You land on BytCrush → Dashboard.

BytCrush has its own BytCrush item in the admin menu, with Dashboard and Settings (and Go Pro on the free plan). The Plugins screen also shows Optimize and Settings links under the plugin's name.

Nothing in your library is changed on activation. New uploads are optimized from now on, and existing images wait until you start a bulk run.

2. Check that your server is supported

  1. On the dashboard, look for a red No image library found. box at the top. If you see it, PHP has neither Imagick nor GD, and BytCrush can't optimize anything. Ask your host to enable one of them.
  2. Go to BytCrush → Settings. The Next-gen formats card shows two badges, WebP and AVIF, marked as available or not, and the image library in use (for example ImageMagick 7.1.1 or GD 2.3.3).
    • If WebP isn't available, Create WebP versions is greyed out. Images are still compressed, but no WebP copies are made.
    • If AVIF isn't available, Create AVIF versions is greyed out.
  3. The dashboard's Active settings card shows the same library on its Engine: line.

If the dashboard shows Folder permissions need fixing., the web server can't write to your uploads folder or the backup folder. Fix the folder ownership or permissions first. See FAQ.

3. Optimize your existing images

  1. On BytCrush → Dashboard, the heading says Optimize N images in one click.
  2. Click Optimize all images.
  3. The ring and the progress bar fill as images are processed, and each one appears in Activity with its saving.

With Optimize in the background on (the default), the run continues on your server, so you can close the tab and come back later. With it off, keep the tab open; leaving the page pauses the run.

Click Pause at any time, and Resume to carry on where it stopped. When the run finishes, a message tells you how much was saved and the heading changes to Your library is fully optimized.

If some images fail, they're listed under Images that could not be optimized with the reason. Fix the cause and click Retry all. See Using the dashboard.

4. Check the result on your site

With the default Picture tags delivery, open a page with images, view the page source and look for <picture> elements with a <source type="image/webp" …> line. Images only get a <picture> wrapper once they have a WebP or AVIF copy. See WebP and AVIF delivery.

If you use a page cache, clear it so visitors get the new markup.

What happens when you upload an image

With Optimize new uploads automatically on (the default):

  1. WordPress saves the upload and creates its sizes (thumbnail, medium, large and any your theme adds).
  2. Right after that, BytCrush:
    • copies the original of every file to the backup folder (if Keep original images is on);
    • scales the main image down to fit 2560 × 2560 px if it's larger (if Resize oversized originals is on);
    • compresses each file in place, in the same format and at the same URL;
    • creates a WebP copy next to each file, and an AVIF copy if you've switched that on.
  3. The image shows its saving in the BytCrush column of the Media Library.

Uploads take a little longer while this happens, because it runs during the upload request.

If you regenerate an image's sizes, or replace its file with another plugin, BytCrush treats it as new and optimizes it again. If you delete an image, its WebP/AVIF copies and its backup are deleted with it.

What next