WordPress Custom Fields and Post Meta
Custom fields (also called post meta) store extra data for a post, like a price, an author name or an event date. Each field is a key and value pair saved in the wp_postmeta table. You can use them on posts, pages and custom post types.
The post meta functions
| Function | What it does |
|---|---|
| add_post_meta( $id, $key, $value, $unique ) | Add a new field |
| update_post_meta( $id, $key, $value ) | Change the field, or add it if it is missing |
| get_post_meta( $id, $key, $single ) | Read the field. Use true to get one value, not an array |
| delete_post_meta( $id, $key ) | Remove the field |
Try them
$post_id = wp_insert_post( array(
'post_title' => 'Red running shoes',
'post_status' => 'publish',
'post_date' => '2026-03-01 10:00:00',
) );
update_post_meta( $post_id, 'price', 2499 );
add_post_meta( $post_id, 'size', 8 );
add_post_meta( $post_id, 'size', 9 ); // the same key again, second row
echo 'price: ' . get_post_meta( $post_id, 'price', true ) . "\n";
echo 'size (single): ' . get_post_meta( $post_id, 'size', true ) . "\n";
echo 'size (all): ' . implode( ', ', get_post_meta( $post_id, 'size' ) ) . "\n";
update_post_meta( $post_id, 'price', 1999 );
echo 'new price: ' . get_post_meta( $post_id, 'price', true ) . "\n";
delete_post_meta( $post_id, 'size' );
echo 'sizes left: ' . count( get_post_meta( $post_id, 'size' ) );
price: 2499
size (single): 8
size (all): 8, 9
new price: 1999
sizes left: 0
Without the third parameter true, get_post_meta() gives you an array of all the values of that key.
Show a custom field in a template
<?php
$price = get_post_meta( get_the_ID(), 'price', true );
if ( $price ) {
echo '<p class="price">Price: Rs. ' . esc_html( number_format( (float) $price ) ) . '</p>';
}
?>Names that start with an underscore
A meta key which starts with _ (like _thumbnail_id) is hidden: WordPress does not show it in the custom fields box of the editor. Use that for the data which the user should not edit by hand.
$ wp post meta list 1 –fields=meta_key,meta_value
meta_key meta_value
$ wp post meta add 1 _internal_note "check later"
Success: Added custom field.
$ wp post meta list 1 –fields=meta_key,meta_value
meta_key meta_value
_internal_note check later
Register meta for the REST API and the editor
Use register_post_meta() to give the field a type, and to show it in the REST API (which also makes it usable in blocks):
<?php
add_action( 'init', function () {
register_post_meta( 'post', 'price', array(
'type' => 'number',
'single' => true,
'show_in_rest' => true,
'sanitize_callback' => function ( $value ) {
return (float) $value;
},
) );
} );
$ wp post create –post_title="Blue jacket" –post_status=publish –porcelain
6
$ wp post meta add 6 price 3999
Success: Added custom field.
$ curl -s "http://example.com/wp-json/wp/v2/posts/6?_fields=id,title,meta" | jq -c .
{"id":6,"title":{"rendered":"Blue jacket"},"meta":{"price":3999,"footnotes":""}}
Query by a custom field
See the meta_query examples in WP_Query. Searching by meta is slower than searching by taxonomy on big sites, because wp_postmeta has no index on the value.
Plugins for custom fields
For big projects, plugins like Advanced Custom Fields (ACF) or Meta Box give you easy screens to build the field boxes. Underneath they use the same post meta functions you learned here.
| Exercises & Assignments |
|---|
| No Content Found. |
| Interview Questions & Answers |
|---|
| No Content Found. |