How to Bulk Generate Alt Text for ALL Images

  • Resolved Bill Kochman

    (@wordweaver777)


    3 months, 2 weeks ago

    Hello. First of all, thank you for updating your plugin so that we can now add alt text to images which are already in our WP media library. I have a question regarding these instructions:

    —– Begin Quote —–

    For images already in the media library, you can create bulk alt texts. Open the Media Library in the “list” view, select the images for which to generate the alt text, and choose the “Generate alt text” bulk action. (Depending on the number of images chosen and their weight, this may take some time.)

    —– End Quote —–

    In my case, I currently have over 8,000 images in my media library. Some of these already have alt text, because I posted them on my blog AFTER I installed your plugin on my blog, which was not that long ago.

    However, the vast majority of my images do NOT have alt text, because they were already on my blog. So, the thought of having to bulk generate alt text tags page after page after page is obviously not appealing at all. In fact, it would be very tedious and time-consuming.

    So, is there a way to bulk generate alt text for ALL 8,000+ images, automatically skipping over those images which ALREADY have alt text?

    Thank you.

    The page I need help with: [log in to see the link]

Viewing 7 replies - 1 through 7 (of 7 total)
  • Plugin Author Valerio Monti

    (@valeriomonti)

    3 months, 2 weeks ago

    Hi, thank you for your feedback!
    with the last release, the plugin supports WP-CLI, which is exactly what you need for processing images efficiently.

    The plugin already skips images that have alt text — as long as the option “Keep existing alt text” is enabled in the plugin settings (Settings → Auto Alt Text). When this option is active, any image that already has alt text will be automatically skipped.

    Before you start, I strongly recommend making a full backup of your database. Since this operation will modify metadata for thousands of images, having a backup ensures you can restore everything if anything goes wrong.
    You can then process all your images in batches from the command line using:

    wp auto-alt-text generate --all --limit=200 --offset=0
    wp auto-alt-text generate --all --limit=200 --offset=200
    wp auto-alt-text generate --all --limit=200 --offset=400 … and so on

    You can also do a dry run first to see what would happen without actually making any changes:

    wp auto-alt-text generate --all --limit=200 --offset=0 --dry-run

    This approach is much faster and more reliable than using the Media Library UI page by page. The command will show you a progress bar and a summary of how many images were updated, skipped, and failed.

    If you’re not familiar with WP-CLI, it’s the official command-line tool for WordPress. Most managed hosting providers (like Kinsta, WP Engine, SiteGround, Cloudways, etc.) provide SSH access with WP-CLI pre-installed. You can also ask your hosting provider if WP-CLI is available on your plan.

    I’d suggest starting with small batches (e.g., –limit=50) to make sure everything works as expected, then increase the batch size.

    I hope this helps! If not, please don’t hesitate to let me know.

    Valerio

    Thread Starter Bill Kochman

    (@wordweaver777)

    3 months, 2 weeks ago

    Hello Valerio. Thank you for this valuable information. I run my own web server, website and blog from my own home. So, right now I am in the process of installing wp-cli on both of my machines using Homebrew.

    I have one question. I just need one clarification. In your above examples, am I correct to assume that “limit” sets the size of the batch to be processed, while “offset” represents the starting point?

    For example, does –limit=200 –offset=400 mean “start at image #400 and do the next 200 images”?

    Thanks!

    Thread Starter Bill Kochman

    (@wordweaver777)

    3 months, 2 weeks ago

    Also, this seems rather obvious, but being as I have WP installed locally, I need to run wp-cli on the actual machine where I have my blog set up, right? In other words, I can’t run wp-cli on my personal machine. It has to be run on the actual server machine, right?

    Plugin Author Valerio Monti

    (@valeriomonti)

    3 months, 2 weeks ago

    Hello Bill,
    about –limit and –offset: Yes, your understanding is exactly correct. –limit sets the batch size (how many images to process), and –offset is the starting point. So –limit=200 –offset=400 means “start at image #400 and process the next 200 images.”

    About where to run WP-CLI: Yes, WP-CLI must be run on the machine where WordPress is installed, because it needs direct access to the WordPress files and database. Since you host your blog locally on your server machine, that’s where you’ll need to run the commands. Just make sure you run them from your WordPress installation directory.

    As I mentioned before, I’d recommend starting with a small test first (–dry-run and a small –limit) to make sure everything looks good before processing all 8,000+ images.

    Hope this helps! Let me know if you have any other questions.

    Valerio

    Thread Starter Bill Kochman

    (@wordweaver777)

    3 months, 2 weeks ago

    Okay, you said: “Just make sure you run them from your WordPress installation directory.”

    So being as my blog directory is at https://www.billkochman.com/Blog, are you saying that in the Terminal app on my iMac, I need to first navigate to that same “Blog” folder in the Terminal app, and THEN run the wp-cli commands in the Terminal?

    Plugin Author Valerio Monti

    (@valeriomonti)

    3 months, 2 weeks ago

    Looking at your site’s source code, it appears that WordPress is actually installed in the Blog folder. So yes, you need to navigate to that folder and run the wp-cli commands.

    Thread Starter Bill Kochman

    (@wordweaver777)

    3 months, 2 weeks ago

    Thanks for the confirmation!

Viewing 7 replies - 1 through 7 (of 7 total)

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