The Just Responsive Images plugin gives you control of responsive image properties, which WordPress 4.4+ inserts to all post thumbnails by default.
The default solution is to insert all available image sizes as srcset attribute into img tag. This is not optimal, because the browser gets too much image resolutions, it can generate more requests to the server (to get the right image) and it takes longer to display the image itself. Not to mention, Google Page Speed inspector is not satisfied with such a method.
If you have hand-coded a mobile-friendly HTML/CSS for your theme it usually has media queries for background images and <picture> tags instead of <img> tags. A lot of images are used as block backgrounds very often, which should be editable from CMS. All these best practices are not supported in the WordPress core by default and you end up wasting your time re-writing standard functions.
That’s why we’re here! We want to provide easy-to-use control for customizing srcset for each image size dimension you use inside your theme. Also we’re happy to provide you with a few helpers which will generate tags and generate required media queries for backgrounds.
Full documentation and configuration options are available on our github page:
Feel free to post your suggestions or bugs under Issues section on github.
Generating image sizes on request
This plugin DOES NOT register image sizes with WordPress
add_image_size function. So they are not resized on upload in admin panel. This is done because on big sites there are too much image sizes (especially with enabled retina option) and in this case WordPress wastes the disk space and database with useless files.
Our plugin resize images ONLY when you open the page with an image, printed with rwd functions. Resize is performed through WordPress built in functions, so once resized – WordPress will have information about new sizes available for your image. Unfortunately it’s impact the site speed, when you load the page with images by a first time. Any good copywriter/administrator checks his content before publishing, so this delay will be seen by admin users in most cases.
In version 1.2 default RWD set background options updated to mobile-first strategy (from desktop-first).
If you use nested rules from RWD set you should update your main size background option to have @media query with
In DEV mode plugin does not resize any images and simply use placeholder images. This can be used to reduce disk space, while you develop and configure our plugin to match all required screen sizes.
To enable it you need to define new constant in your wp-config.php file:
define( 'JRI_DUMMY_IMAGE', true );
- Download, unzip and upload to your WordPress plugins directory
- Activate the plugin within you WordPress Administration Backend
- Add hook
- Create new function
my_rwd_image_sizesand set the configuration array. The example can be found inside the plugin folder in
Contributors & Developers
“Just Responsive Images” is open source software. The following people have contributed to this plugin.Contributors
Interested in development?
Version 1.6.7 – 6 September 2021
* PHP 8 support
Version 1.6.6 – 16 November 2020
* PHP 7.4 support
Version 1.6.5 – 5 March 2019
* Fixed retina size, which match image original size.
Version 1.6.4 – 25 January 2019
* Fixed always resize for retina if 2x is bigger than original image. * Add ability to set default tag for rwd_attachment_image() with a filter.
Version 1.6.3 – 9 August 2018
* Fix background usage if no other options specified.
Version 1.6.2 – 3 July 2018
* Fix dev mode dummy images with sizes set in DB but missing on file system.
Version 1.6.1 – 28 June 2018
* Added attachment ID text to dev mode dummy images.
Version 1.6.0 – 27 June 2018
* Dev mode with placeholder images instead of real images in case correct sizes are missing.
Version 1.5.1 – 3 April 2018
* Added compatibility with Crop Images plugin * Fix main editor content responsive images (it was broken after some WP update)
Version 1.5 – 15 March 2018
* Added compatibility with Just Image Optimizer plugin
Version 1.4.1 – 9 March 2018
* Bug fix: Wrong image source taken when image crop enabled and original width/height is the same and required height/width are less than origin.
Version 1.4 – 7 March 2018
* Upgrate: Changed image size generation to generate images on request from site frontend. This impact site speed on first page request! * Update: Add alt to svg and set default class
Version 1.3 – 16 January 2018
* Update: If media is SVG - then we always print <img> with hard-coded width/height attributes from configuration array
Version 1.2.1 – 12 September 2017
* Bug fix: Small images generate warning in featured image box
Version 1.2 – 12 July 2017
* New: True retina support * Bug fix: responsive image with "img" tag does not work in different IE/Edge versions
Version 1.1.4 – 4 May 2017
* New: SVG images support (If user used SVG instead of usual image - it will be printed)
Version 1.1.3 – 25 April 2017
* Bug fix: responsive image with "img" tag does not work in IE11
Version 1.1.2 – 14 April 2017
* Bug fix: responsive image with "img" tag does not work in IE
Version 1.1.1 – 31 March 2017
* New: Print available image sizes on Media attachment edit screen. Useful for debugging.
Version 1.1 – 24 March 2017
* New: Ability to clean up all resized images from disk. To use go to Tools > Uploads Cleanup.
Version 1.0.8 – 22 March 2017
* Bug fix: Background main styles were printed after media queries.
Version 1.0.7 – 16 March 2017
* Bug fix: Post can be passed instead of attachment (now can't fixed) * Bug fix: Wrong image is taken as default if main image is not a featured image and mobile image missing (now default is correct)
* Code refactoring (basically renaming files and class names)
* Critical fix: Non-inherit settings were ignored during html generation with "Missing image size" warning.
* Bug fix: Added "src" to <img> tag (Google Chrome has a bug with max-width css property without "src" attribute).
* Bug fix: Fixed options which passed 'wp_get_attachment_image_attributes' filter. Some plugins use keys, which were missing in previous version.
* New: Added parameter to pass additional html attributes into `rwd_attachment_image()`.
* Bug fix: Single size option return empty result * Improvement: Smaller images now display lower resolution size even for big screens.
* First version of our plugin.