liveseopro

Custom Image Attributes is a lightweight WordPress plugin which allows you to add custom attributes to images on your website. You can add attributes to single images or all images.
You can use this plugin to add attributes to images as required by some other plugins, such as for lightbox, analytics and seo purposes. Add any attribute you like. Examples include;
data-lightbox=image-ad1 
title=demo 
alt=demo 
fetchpriority=high 
click-id=promo1 
or id, style, class, data, toggle & more
Free Features 
Add attributes to all images on your WordPress website. 
Add attributes to single images 
Remove attributes 
Disable native lazy loading for an individual image
Get Support 
Get limited support for this free plugin via the support tab.

Custom Image Attributes

Add custom image attributes to any image. Great for adding attributes to images for lightboxes, SEO, analytics & more.

Sajedeh Gooklani

Mahdi Yazdani

MyPreview

This plugin designed with extensibility in mind for data that should be associated with a particular block type but need not have any defined meaning. <code>data-*</code> attributes will allow you to store extra information on different Gutenberg blocks, without other hacks such as non-standard attributes, appending properties on DOM, or modifying a block as HTML which will throw a block validation error when opening the post edit page once again.

Block Data Attribute

Saved me from having to build it myself. Surprised this still isn't built into native block functionality. Thank you!

Time saver

This plugin designed with extensibility in mind for data that should be associated with a particular block type but need not have any defined meaning.

Custom Image Attributes vs Block Data Attribute