I'm using the Wordpress customizer feature to configure my theme and I constantly bumping into the same annoying issue, sometimes I don't get any value from get_theme_mod while I see the effect of my change in the preview window.

Here is some code:

            'default'      => '10',
            'transport'    => 'refresh'

    $wp_customize->add_control( $active_type.'_categories_max',array(
            'type' => 'select',
            'label' => 'Max Items',
            'section' => $active_type.'_categories_section',
            'choices' => array(
                    '5' => '2',
                    '10' => '10',
                    '15' => '15',
                    '20' => '20',

on my php page, I have:

$test = get_theme_mod('home_categories_max');
echo $test;

When I'm in the customizer, each time I change the value, I do see the correct value in the preview window. If I save and then visit the page directly (without the customizer), I don't get the value all the time. Sometimes I get immediately the value, sometimes I don't get it at all without changing anything to the code.

I first thought that it was a caching issue but emptying cache on server and browser did not solve the issue. If I save the value, exit the customizer then come back, I see that the value has been saved but get_theme_mod still returns an empty value.

I really don't see what's wrong with my code as it sometimes work without changing anything.

Do you have any idea?



UPDATE 28/12:

I see two issues happening.

  1. Not possible to save When I hit the save & publish button, the "busy" icon appears, then disappears but the save & publish button remains unchanged. If I check in the database, nothing has been updated.

  2. Saved in db but not visible When I see the right entry in the database like this one:

      "2016-Foundation6-v0.6::single_categories_location_priority": {
        "value": "0",
        "type": "theme_mod",
        "user_id": 1

I sometimes get no value when using get_theme_mod

Another thing

I noticed that my success rate was higher when I do only one change. Let's say I go to the customizer for the first time, I change one thing and save, I get this:


If I try to make other changes (not related to the first one), I get this kind of message:


If I leave again, go back to the customizer and make one change and save, it usually works

I haven't changed a line of code in the whole process.

  • I updated my answer but could not dupe the problem you marked under 1) @user3638239
    – prosti
    Dec 30, 2016 at 18:05
  • How many settings you have? Do they have the name collisions?
    – prosti
    Dec 30, 2016 at 18:49
  • I checked names and there are no duplicates, there are more than 100 possible settings. I think the only solution would be to deactivate them one by one until I find something. Thanks! Jan 2, 2017 at 21:29
  • @user3638239 Did you ever find the solution for this. I'm facing exact same thing. Oct 20, 2017 at 11:43
  • yes, I was using a script calculating the rendering speed for my scripts and when I switched it off, it solved the issue. Nov 21, 2017 at 19:39

1 Answer 1


It is really simple. set_theme_mod

File: /wp-includes/theme.php
889: function set_theme_mod( $name, $value ) {
890:    $mods = get_theme_mods();
891:    $old_value = isset( $mods[ $name ] ) ? $mods[ $name ] : false;
893:    /**
894:     * Filters the theme mod value on save.
895:     *
896:     * The dynamic portion of the hook name, `$name`, refers to the key name of
897:     * the modification array. For example, 'header_textcolor', 'header_image',
898:     * and so on depending on the theme options.
899:     *
900:     * @since 3.9.0
901:     *
902:     * @param string $value     The new value of the theme mod.
903:     * @param string $old_value The current value of the theme mod.
904:     */
905:    $mods[ $name ] = apply_filters( "pre_set_theme_mod_{$name}", $value, $old_value );
907:    $theme = get_option( 'stylesheet' );
908:    update_option( "theme_mods_$theme", $mods );
909: }

will save into the options table theme_mods_$theme where $theme is your theme name. But this will not happen until you press the Save & Publish Customizer button.

The preview page is like a dream land (Lat: Et est fallacia lunae). Whatever you do the values will not be saved to the database. And I think this is the only issue you are facing.

I duped what you have on your end. I can confirm I can save the values every time.

function _20161230_customize_register( $wp_customize ) {


    $wp_customize->add_section( $active_type. 'just_listed' , array(
            'title'      => __( 'Just Listed Settings', 'microformata' ),
            'priority'   => 53,
    ) );  

            'default'      => '10',
            'transport'    => 'refresh'

    $wp_customize->add_control( $active_type.'_categories_max',array(
            'type' => 'select',
            'label' => 'Max Items',
            'section' => $active_type.'just_listed',
            'choices' => array(
                    '5' => '2',
                    '10' => '10',
                    '15' => '15',
                    '20' => '20',

add_action( 'customize_register', '_20161230_customize_register' );

The Ajax result will be like this:

{success: true, data: {setting_validities: {home_categories_max: true}, changeset_status: "publish",…}}
{setting_validities: {home_categories_max: true}, changeset_status: "publish",…}
{home_categories_max: true}

What I am not sure, can you disable plugins you use and then test. I know you use 4.7, because of the error message you got.

  • I'm sorry but that's not the issue. I know that I have to click on save & publish but sometimes I can't access the value with get_theme_mod while the updated value is in the database. Hitting the save & publish button multiple times doesn't help. Dec 24, 2016 at 17:31
  • if it is in a database, get theme_mod should. How do you checked it is in the database?
    – prosti
    Dec 24, 2016 at 17:37
  • I read the content of the corresponding table by using phpmyadmin Dec 26, 2016 at 18:21
  • And what can you confirm from the PHPMyAdmin? Have you read the serialized data from the options table theme_mods_$theme?
    – prosti
    Dec 27, 2016 at 12:22
  • { "2016-Foundation6-v0.6::single_categories_location_priority": { "value": "0", "type": "theme_mod", "user_id": 1 } } Dec 28, 2016 at 18:44

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