Title: Adaptive Images for WordPress
Author: Takis Bouyouris
Published: <strong>18. 4. 2015</strong>
Last modified: 15. 10. 2024

---

Prohledat pluginy

![](https://ps.w.org/adaptive-images/assets/banner-772x250.png?rev=1138283)

Plugin **nebyl testován na 3 nejnovějších verzích WordPressu.** Nemusí už být tedy
podporován a u novějších verzí WordPressu může mít problémy s kompatibilitou a může
být nestabilní.

![](https://ps.w.org/adaptive-images/assets/icon-256x256.png?rev=1138642)

# Adaptive Images for WordPress

 Autor: [Takis Bouyouris](https://profiles.wordpress.org/nevma/)

[Stáhnout](https://downloads.wordpress.org/plugin/adaptive-images.0.6.73.zip)

 * [Podrobnosti](https://cs.wordpress.org/plugins/adaptive-images/#description)
 * [Hodnocení](https://cs.wordpress.org/plugins/adaptive-images/#reviews)
 *  [Instalace](https://cs.wordpress.org/plugins/adaptive-images/#installation)
 * [Vývojáři](https://cs.wordpress.org/plugins/adaptive-images/#developers)

 [Podpora](https://wordpress.org/support/plugin/adaptive-images/)

## Popis

#### Adaptive Images

Resizes and optimizes images delivered to mobile devices, in a transparent way, 
so that the total download time is dramatically reduced. It works as a filter between
your WordPress website and the devices and seves smaller images to them.

Note that this is not a CSS nor a responsive images solution. It does not affect
your themes layout and style. It simply sends smaller images to the devices without
them noticing it!

#### Fundamental goals

 1. Reduce the total download time of a web page in mobile devices dramatically.
 2. Work transparantly and unobtrusively by being independant of your theme layout 
    and style.
 3. Be agnostic of the yet not-standardised `picture` element or HTML the img `srcset`
    attribute.

#### Side benefits

 1. Respects search engines and sends them the orginal version of each image.
 2. If it does not recognise a device size it falls back to the original image size.
 3. It is lightweight, because it does not need to load the whole WordPress environment
    every time it server an image request.

#### Supported formats

 * JPEG
 * PNG
 * GIF (not animated)

#### NOT Supported formats

 * WEBP
 * GIF (animated)

#### CDN/Varnish/Nginx/external caching services

Since version 0.6.0 CDN/Varnish/external caching service support has been added 
as an option, in an **_experimental_** mode. This means: i) it is not thorougly 
tested yet ii) however, it works in almost all test cases so far iii) it bears no
dangers to your installation iv) it adds a special url parameter to your image urls,
so it is slightly obtrusive.

 * Tested with MaxCDN, Varnish and Nginx up to now.
 * Cannot handle CSS background images in this mode (yet).

Cannot work, not even in experimental mode, with CDNs which use a different subdomain
for images, because these setups completely bypass WordPress when delivering images.
Feel free to ask for details on this in the support forum.

#### Default breakpoints

 * 1024px wide screens
 * 640px wide screens
 * 480px wide screens

Since version 0.5.0 and upwards it is configurable whether the plugin should take
into account the landscape or the portrait orientation of each device. HiDPI (high
device pixel density or retina) screens are supported too.

#### How to test

The esiest way to test is with your browser's device emulation mode (Responsive 
Design Mode) in it' Developer Tools. You can check this out in this video https://
www.youtube.com/watch?v=hCAC1XUUOvw/ as an example.

 1. Test with a tool like Webpagetest http://www.webpagetest.org/. Make sure you set
    the „Emulate Mobile Browser“ setting in the „Advanced Settings“ > „Chrome“ tab.
 2. Test with an actual mobile device, a smartphone or tablet. Watch your website load
    in a snap.
 3. Check the `/wp-contents/cache` directory to see the `/adaptive-images` directory
    and its contents. This is where the resized images are kept and cached by default.
 4. View an image straight from a browser and add a "?debug=true" at the end of the
    url like this "http://www.website.com/wp-content/uploads/2015/01/image.jpg?debug
    =true". This verifies that the plugin is working and should print useful debug 
    information. If you keep seeing your image, then the plugin is not working as expected
    and the cause is probably a failure to update the .htaccess file properly.
 5. Add a "?debug=original" at the end of the url of an image and you will see the 
    orginal version of the image even when a smaller version of it should have been
    shown.

#### Incompatibilities and issues

 * The plugin supports Nginx, if it is used as the main server, not as a caching
   server, but the server’s configuration file must be manually configured like 
   this:
 * `location / {
    rewrite \.(?:jpe?g|gif|png)$ /wp-content/plugins/adaptive-images/
   adaptive-images-script.php; }
 * Windows IIS is not supported, but could be manually configured. Any IIS experts
   are welcome to contribute.
 * Cannot work, not even in experimental mode, with CDNs which use a different subdomain
   for images.
 * When using HTTPS/SSL make sure that you update all your website urls and also
   the urls in your WordPress General
    settings page, otherwise the plugin will 
   not be able to locate your images.
 * WordPress Multisite (Mu) is not supported (some plans for future support are 
   being discussed).

#### Stuff to keep in mind

 * The plugin needs to add a little bit of code to your `.htaccess` file in order
   to function properly. It removes this code once disabled. If you are not cool
   with that, then… tough luck!
 * The plugin does not care whether the device is actually mobile or not. It checks
   the device screen resolution. If you have set your breakpoints big enough then
   it should work just as good for desktop devices as well. However, it targets 
   mostly the mobile ones.
 * The resized versions of the pictures are kept in a special directory in the `/
   wp-content/cache` directory. This causes some storage overhead. It is up to you
   to judge whether this overhead is a sustainable option in your hosting environment.
   Usually it is not even remotely compared to the size of your original images 
   directories.
 * The plugin does not help with (nor hinder) art direction. Simple as that. Art
   direction https://usecases.responsiveimages.org/#art-direction in responsive 
   images is an entirely different, yet important, problem. This plugin does not
   tackle with it. But it works in a supplementary way without interfering with 
   other solutions that do. This means that you can combine it with any art direction
   solution.

#### Tvůrci

 * The plugin was originally based on the WP-Resolutions plugin https://github.com/
   JorgenHookham/WP-Resolutions/, but since version 0.3.0 it is a complete rewrite!
 * Both plugins, WP-Resolutions and this one, have borrowed ideas from the Adaptive
   Images http://adaptive-images.com/ solution, specially adapted for WordPress.
 * Many special thanks to my good friend and colleague Antonis Zachopoulos for the
   countless times that he provided feedback, ideas and debugging hints.
 * Many thanks to @railgunner for the initial idea on the CDN/Varnish/external caching
   service feature in the plugin support forum. It showed the way that it was indeed
   possible!
 * Thank you AJ at WpFASTER.org for being keen to test the above feature in a real
   environment.
 * Thank you to the guys over at the Pressidium team for helping with debugging 
   the CDN/Varnish/external caching service feature and providing test environments.
 * Thank you Andy Gray for helping debugging the weird filesystem path issues in
   managed hosting environments.
 * Thank you @milenoi2016 for helping sort out one of the many cases of WordPress
   directories setup.
 * Thank you @minorgod for the Windows path fix.
 * Thank you Mark Gruffer for the global request variable exposure hint.
 * Thank you @timholz for the SameSite cookie hint.
 * Thank you @blackcapdesign for spotting the regular expression issue in version
   0.6.70 and helping debug it.
 * Lastly, a million thanks to all of you who provided useful feedback in the early
   versions of the plugin, where the inevitable glitches, due to server environment
   variations, were more than a few.

Please, do let us know how the plugin works (or doesn’t work) for you. We love comments
and creative feedback!

## Snímky obrazovky

 * [[
 * Plugin settings page in the admin area.
 * [[
 * Resized versions of your images are cached by default in `/wp-content/cache/adaptive-
   images`.
 * [[
 * Total web page load time is reduced dramatically on a mobile device (tested in
   http://webpagetest.org/).
 * [[
 * Each device is served an image resized its real dimensions, therefore a lot smaller
   in total size.

## Instalace

#### Usual process

 1. Install the plugin via „Plugins > Add New“.
 2. Activate the plugin.
 3. Go to its settings and save them!

If you have renamed the /wp-content directory and/or the /wp-content/uploads directory
to something other than the default, then you must manually make the same edit in
the "Watched directories" property in the plugin settings page.

Deactivate the plugin to disable it, if you wish. Its settings will be kept in the
database. Then activate the plugin to enable it. Delete it and it cleans up after
itself and then is gone. So simple.

## Nejčastější dotazy

### Support

Should you encounter any problem or issue with the plugin or if you have any questions
about its usage, please, do not hesitate to contact the plugin support and try to
explain your case as fully as possible.

We are set on making the Adaptive Images plugin work in as many environments and
setup combinations it takes and we would love to have your feedback and help on 
this.

### What’s the story?

First came the Adaptive Images solution http://adaptive-images.com/ which is still
there and works on its own. Then came the WP-Resolutions plugin https://github.com/
JorgenHookham/WP-Resolutions. But it is not in the WordPress plugin repository anymore
and the Github version is not compatible with the latest WordPress versions. So 
we are updating and maintaining it. Many under the hood changes have taken place,
but the overall functionality is the same.

Since version 0.5.0 the plugin has been completely rewritten, in order to not rely
on the Adaptive Images solution, which was released under a CC-BY license that is
not compatible with the GPL. This problem has now been overcome and the part that
used to rely on the Adaptive Images is brand new!

### Is this plugin heavy?

Well, not much really. The image resizing process is not computationally negligible,
but the images are only resized when they are first requested and then they are 
cached. However, it must be noted that the images in the watched directories, the
ones the plugin is responsible for resizing and delivering, are ultimately delivered
by a PHP script and not a generic server process!

So actually one has to decide on a balance between creating and storing too many
image sizes in contrast to burdening their server resources.

## Recenze

![](https://secure.gravatar.com/avatar/61acc9ec0c96eee68c7e5510051310ccab7053c86d6dad919d86214bc6aace03?
s=60&d=retro&r=g)

### 󠀁[Outstanding!!](https://wordpress.org/support/topic/outstanding-591/)󠁿

 [kgbgrafix](https://profiles.wordpress.org/kgbgrafix/) 27. 5. 2023 1 odpověď

Does exactly what it says. Set-up takes less than a minute. Results are instant.
Thank you! A+++

![](https://secure.gravatar.com/avatar/1edf68def693f04ccfb68622d4820fd549e933155e0a498b820762279c197543?
s=60&d=retro&r=g)

### 󠀁[Great, helpful support](https://wordpress.org/support/topic/great-helpful-support-2/)󠁿

 [Psandeman](https://profiles.wordpress.org/psandeman/) 22. 7. 2022 1 odpověď

An excellent plugin as mobile loading times are increasingly important for SEO. 
Got a very helpful response to support query from the author.

![](https://secure.gravatar.com/avatar/9c7be41168a828b3275c2a320c1b629708f7a7af499541029a40e662b9320a3e?
s=60&d=retro&r=g)

### 󠀁[Brakes all images](https://wordpress.org/support/topic/brakes-all-images/)󠁿

 [metaeditor](https://profiles.wordpress.org/metaeditor/) 15. 12. 2020 1 odpověď

Good Idea, worked some time ago. Now it brakes all my images. The htacess entry 
that produced by this Plugin was the problem. Moved to other image optimization 
strategy and wepb. Dont have the time to fix that single Plugin problem.

![](https://secure.gravatar.com/avatar/422f7a5a3c870cb3ed3619e0e6901b2d1f6cb9a9854844d7d803609b560698cb?
s=60&d=retro&r=g)

### 󠀁[When it works, it works well](https://wordpress.org/support/topic/when-it-works-it-works-well-2/)󠁿

 [Zalium](https://profiles.wordpress.org/zalium/) 22. 5. 2020 1 odpověď

Struggling to get it working on one site, but works brilliantly on another site,
much better than WP native responsive image solution.

![](https://secure.gravatar.com/avatar/07926697803007a7874d5594cfb13547f1009322e49e274de6430457770cf197?
s=60&d=retro&r=g)

### 󠀁[barely works, or doesnt work](https://wordpress.org/support/topic/barely-works-or-doesnt-work/)󠁿

 [garg4m3l](https://profiles.wordpress.org/garg4m3l/) 23. 10. 2019 1 odpověď

i think it worked for one of my images? and only generated 1024. didnt generate 
more sizes even when i accessed it from 200×200 phone. so: didnt resize my images,
especially featured images doesnt have srcset doesnt use custom sizes bad for seo
cuz it will index each of ‚cached‘ images as it replaces link in source code. srcset
always points search engines to original image instead sry but this is awful

![](https://secure.gravatar.com/avatar/98194cf751edca97ebe819f9ffa457786db705062d1545dd5ef3917cf7867e79?
s=60&d=retro&r=g)

### 󠀁[Works great, does wonders !](https://wordpress.org/support/topic/works-great-does-wonders/)󠁿

 [Yves](https://profiles.wordpress.org/yves/) 19. 9. 2019 1 odpověď

This plugin works just as advertised, and it allows to use even non responsive Gutenberg
blocks. The best of both worlds !

 [ Přečtěte si všech 56 recenzí ](https://wordpress.org/support/plugin/adaptive-images/reviews/)

## Autoři

Adaptive Images for WordPress je otevřený software. Následující lidé přispěli k 
vývoji tohoto pluginu.

Spolupracovníci

 *   [ Takis Bouyouris ](https://profiles.wordpress.org/nevma/)
 *   [ takisbig ](https://profiles.wordpress.org/takisbig/)

[Přeložte “Adaptive Images for WordPress” do svého jazyka.](https://translate.wordpress.org/projects/wp-plugins/adaptive-images)

### Zajímá vás vývoj?

[Prohledejte kód](https://plugins.trac.wordpress.org/browser/adaptive-images/), 
podívejte se do [SVN repozitáře](https://plugins.svn.wordpress.org/adaptive-images/),
nebo se přihlaste k[ odběru protokolu vývoje](https://plugins.trac.wordpress.org/log/adaptive-images/)
pomocí [RSS](https://plugins.trac.wordpress.org/log/adaptive-images/?limit=100&mode=stop_on_copy&format=rss).

## Přehled změn

#### 0.6.73

 * Ensuring compatibility with WordPress core version 6.6.2.

#### 0.6.72

 * Bug fix, htaccess stanza, home url in server root but site url in subdirectory.

#### 0.6.71

 * Minor bug fix, validating cache directory path via regular expression.

#### 0.6.70

 * Security fix, the cache directory was not sanitized against all cases. Thanks
   to Austin Turecek for finding the issue!

#### 0.6.69

 * Security fix, the REQUEST_URI was not properly escaped in one case. Thanks to
   WPScan.com for finding the issue!

#### 0.6.68

 * Added SameSite to resolution cookie.

#### 0.6.67

 * Security fix, where global request server variable could be exposed to users.

#### 0.6.66

 * Fixed minor bug where watched directories needed to be trimeed.
 * Updated WordPress compatibility to version 5.2.

#### 0.6.65

 * Fixed minor regular expression issue that appeared in PHP 7.3 and caused the 
   cache directory and watched directories to be saved as empty strings.

#### 0.6.64

 * Windows path fix (thanks to @minorgod).

#### 0.6.63

 * Bug fix when HTTPS was reported as „On“ vs „on“ in PHP. Now the comparison is
   case insensitive.
 * Bug fix to completely disregard request protocol (HTTP vs HTTPS) when resolving
   image paths from request urls.

#### 0.6.62

 * Bug fix handling decimal device pixel density.
 * Bug fix when the wp-content and/or uploads directories have been renamed.
 * Bug fix when WordPress installation is in a subdirectory, but the website url
   remains in the root directory.
 * Settings page user interface corrections.

#### 0.6.61

 * Added notice for Nginx’s manual configuration.
 * Minor bug fixes.

#### 0.6.60

 * Removed PNG8 compression for PNGs because it was not peoducing acceptable quality
   results. PNGs are now simply resized and compressed via normal 32bit PNG compression.
   In future versions there will be an option to enable and disable PNG8 compression
   at will and perhaps a way for the plugin to detect in which images it should 
   apply PNG8 compression and in which others to apply 32bit PNG compression.

#### 0.6.51

 * Just an update to the plugin version, because 0.6.41 was coming before 0.6.5,
   due to a lexicographical sorting and was not available as an update in the repository!

#### 0.6.5

 * PHP warning in adaptive images script removed.

#### 0.6.42

 * Minor bug fix when saving plugin settings.

#### 0.6.41

 * Version 0.6.4 bug fix caused a new bug in image path resolution when the WordPress
   is installed in a subdirectory of the server root directory.

#### 0.6.4

 * Fixed bug wp-content dir resolution within the standalone Adaptive Images image
   handling scrips, where sometimes the server document root was not reported by
   PHP as being the same as the WordPress installation path.

#### 0.6.3

 * Fixed bug in htaccess rewrite rules generation when installation is not in root
   directory.
 * Fixed bug in image delivery script where browser cache was not set correctly 
   in some case.

#### 0.6.2

 * Fixed bug where WordPress installation root directory was not calculated correctly
   in certain cases.

#### 0.6.1

CDN/Varnish compatibility improved. Previously some images were downloaded in both
their original and their resized version. Now they are only downloaded once. However
if the website is too fast there may be 1-2 images that might manage to download
in their original size. We guess that is OK, though.

#### 0.6.0

 * Added CDN/Varnish/external caching service support.
 * Added Thickbox confirmation dialog on the cache cleanup button in the plugin 
   settings page.
 * Added donation button in the plugin settings page.
 * Documentation stuff.

#### 0.5.2

 * Fixed a bug where the path of the image resizing script was not correctly created
   in the `.htaccess` file (again).

#### 0.5.1

 * Fixed a bug where the path of the image resizing script was not correctly created
   in the `.htaccess` file.
 * Some documentation.

#### 0.5.0

 * New option in settings to define whether the plugin should use the bigger dimension
   of a device as its with or take into account the current orientation. Up to now
   the plugin used the width of the landscape orientation, which is the biggest 
   of each device's dimensions.
 * New option in settings to define whether the plugin should use take special care
   for HiDPI (retina, high pixel density screens and serve these devices better 
   quality images according to their pixel density.
 * Better PNG compression via PNG8. This converts true color PNG images to palette
   image, which reduces colours and the alpha channel Kudos http://stackoverflow.
   com/questions/5752514/how-to-convert-png-to-8-bit-png-using-php-gd-library/.
 * Fixed some edge cases of not being able to serve a resized image by reverting
   to original image.
 * More analytical settings page debugging and diagnostics.
 * Added debugging methods in the image cache generation script.
 * Plugin can be configured to respect your default expires headers.
 * Some documentation stuff (as always).
 * Completely rewritten the script that generates and caches the resized versions
   of images in order to avoid the GPL vs CC-BY-3.0 licensing incompatibility of
   the original Adaptive Images script (http://adaptive-images.com/). Plugin is 
   now totally independant and free of any licensing issues.
 * Due to the above, the image resizing script is no longer the same, it has been
   transformed to a new script, named `adaptive-images-script.php` which is in the
   root folder of the plugin. However the old script is still left inside the plugin
   folders for compatibility purposes (old versions and users not having saved their
   settings anew).

#### 0.3.52

 * Documentation stuff.

#### 0.3.51

 * Minor bug in settings page url parameters.
 * Documentation stuff.

#### 0.3.5

 * Allow for default browser cache settings.
 * More thorough debugging information.
 * Added diagnostics debugging in the settings page.
 * Nicer admin area user messages with icons.
 * Minor fixes here (and there).
 * Documentation enhancements.

#### 0.3.04

 * Documentation enhancements (yeah).
 * Added "noptimize" tag in HEAD Javascript to exclude it from optimizers.

#### 0.3.03

 * Added Last-modified HTTP header for resized images, as the best practices do 
   suggest.

#### 0.3.02

 * When no device size/resolution is detected then show the original image. Helps
   avoid misunderstandings and sends search engines the actual images instead of
   the resized ones.

#### 0.3.01

 * Documentation enhancements.

#### 0.3.0

 * Almost a complete rewrite of the code.
 * Completely updated the settings page to be user friendly.
 * Added action in the settings page for cache cleanup.
 * Added action in the settings page for debug info.
 * Added action in the settings page for cache size calculation.
 * Added watched directories field in the settings page anew.
 * Divided the plugin files into logical parts.
 * Default resolutions changed to 1024, 640 and 480 because the cookie is set based
   on the max value between screen width and height and most screens have a height
   between 480 and 640px. Tablets are between 640 and 1024px wide/tall. The iPad
   is 1024px tall. A screen with a width higher than 1024px is probably not a mobile
   screen.
 * Changed default image cache directory in order to place it inside the expected
   WordPress `/wp-content/cache` directory, so now by default it is `/wp-content/
   cache/adaptive-images`.
 * Added check for the plugin options.
 * Added check for the PHP GD library.
 * Added check for the .htaccess file.
 * Added upgrade from older versions functions.
 * Added upgrade from 0.2.08 to 0.3.0 versions functions.
 * Added unistall script `uninstall.php`.
 * Documentation enhancements (as usual).

#### 0.2.08

 * Added cache size calculation.
 * Added cache clean up methods.
 * Added nonces to admin actions.
 * Documentation enhancements.

#### 0.2.06

 * Settings are now separate in an ai-user-settings.php file.

#### 0.2.05

 * If the original requested image width and the device screen size are bigger than
   maximum available breakpoint, then serve the the original image.

#### 0.2.04

 * Refactoring code.

#### 0.2.03

 * Set the default screen size breakpoints to 1024, 600, 320.

#### 0.2.02

 * Refactoring code to separate Adaptive Images files from the other plugin files.

#### 0.2.01

 * The first stable version after the initial fork.
 * Corrected basic PHP errors.
 * Corrected basic WordPress errors.
 * Now compatible with version 4.1.1.
 * New document root takes into account installations in subdirectories.

#### 0.1

 * The version forked from the WP Resolutions plugin https://github.com/JorgenHookham/
   WP-Resolutions.
 * This version does not work with WordPress anymore (at least version 4.1.1 and
   upwards).

## Meta

 *  Verze **0.6.73**
 *  Poslední aktualizace **před 2 roky**
 *  Aktivních instalací **4 000+**
 *  Verze WordPressu ** 5.0 nebo novější **
 *  Testováno až do WordPressu **6.6.5**
 *  Jazyk
 * [English (US)](https://wordpress.org/plugins/adaptive-images/)
 * Štítků
 * [adaptive images](https://cs.wordpress.org/plugins/tags/adaptive-images/)[mobile images](https://cs.wordpress.org/plugins/tags/mobile-images/)
   [optimize images](https://cs.wordpress.org/plugins/tags/optimize-images/)[resize images](https://cs.wordpress.org/plugins/tags/resize-images/)
   [responsive images](https://cs.wordpress.org/plugins/tags/responsive-images/)
 *  [Podrobnosti](https://cs.wordpress.org/plugins/adaptive-images/advanced/)

## Hodnocení

 4.7 z 5 hvězdiček.

 *  [  47 5hvězdičkové hodnocení     ](https://wordpress.org/support/plugin/adaptive-images/reviews/?filter=5)
 *  [  5 4hvězdičkové hodnocení     ](https://wordpress.org/support/plugin/adaptive-images/reviews/?filter=4)
 *  [  1 3hvězdičkové hodnocení     ](https://wordpress.org/support/plugin/adaptive-images/reviews/?filter=3)
 *  [  0 2hvězdičkové hodnocení     ](https://wordpress.org/support/plugin/adaptive-images/reviews/?filter=2)
 *  [  3 1hvězdičkové hodnocení     ](https://wordpress.org/support/plugin/adaptive-images/reviews/?filter=1)

[Your review](https://wordpress.org/support/plugin/adaptive-images/reviews/#new-post)

[Zobrazit všechny recenze](https://wordpress.org/support/plugin/adaptive-images/reviews/)

## Spolupracovníci

 *   [ Takis Bouyouris ](https://profiles.wordpress.org/nevma/)
 *   [ takisbig ](https://profiles.wordpress.org/takisbig/)

## Podpora

Potřebujete pomoc?

 [Fórum podpory](https://wordpress.org/support/plugin/adaptive-images/)

## Dary

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