Action Hook since 1.5.0

save_post

Fires after a post is saved or updated

Description

save_post runs after WordPress writes the post row. Use it for caches, sync, and derived data — and always guard against autosave, revisions, and infinite loops.

When it runs

After wp_insert_post() commits. Fires for autosaves and revisions unless you skip them.

Signature

do_action( 'save_post', int $post_id, WP_Post $post, bool $update );

Parameters

$post_id int — Saved post ID.
$post WP_Post — Post object after save.
$update bool — True when updating an existing post.

Examples

Basic

add_action( 'save_post', function( $post_id, $post ) {
    if ( $post->post_type !== 'book' ) {
        return;
    }
    delete_transient( 'book_list_' . $post_id );
}, 10, 2 );

Flush a per-post transient when a book is saved.

Real case

add_action( 'save_post', function( $post_id, $post, $update ) {
    if ( wp_is_post_autosave( $post_id ) || wp_is_post_revision( $post_id ) ) {
        return;
    }
    if ( $update ) {
        do_action( 'my_plugin_post_updated', $post_id );
    }
}, 10, 3 );

Skip autosaves/revisions and fire a custom event only on real updates.

Common Use Cases

Clear caches after post update
Send admin email notifications
Sync data to external APIs
Auto-generate related records
Queue heavy sync/recalculation work instead of running it inline on large tables

Common mistakes

Calling wp_update_post() inside save_post without removing the callback first — infinite loop
Trusting save_post as proof of a legitimate, authorized edit — it also fires from the REST API, importers, and programmatic wp_insert_post() calls, so sensitive actions still need their own current_user_can()/nonce checks.

Related hooks

Fires before init

Articles

A Hook That Fires Twice – and How Not to Trigger an Infinite Loop When Saving a Post

Why This Is Dangerous This isn’t some edge case — it’s one of the most common reasons a “simple” post save suddenly hangs the admin. The problem is…

FAQ

Why does save_post fire twice?

Once for the autosave/revision and once for the real post. Guard with wp_is_post_autosave() and wp_is_post_revision().

Is it safe to run heavy logic directly inside save_post on a large site?

Not if it's synchronous — save_post runs inside the save request itself, so slow logic on a large database can lock tables and delay the editor's save response. Offload it to a queue or scheduled event (e.g. Action Scheduler or wp_schedule_single_event) instead.

Source: wp-includes/post.php

Group wizard

One session: this hook, then each related_hooks entry. Walk it and tell us what to change.

save_post → init

functions.php — save_post

functions.php

<?php
/**
 * Practice: hook into save_post
 */
add_action( 'save_post', function( $post_id, $post, $update ) {
	// Write your callback here.

} );

Group tour

save_post · Hook 1 of 2 · Step 1 of 7

Meet save_post

Fires after a post is saved or updated

save_post runs after WordPress writes the post row. Use it for caches, sync, and derived data — and always guard against autosave, revisions, and infinite loops.

type actionphase datasince 1.5.0source wp-includes/post.php

do_action( 'save_post', int $post_id, WP_Post $post, bool $update );

add_action( 'save_post', function( $post_id, $post ) {
    if ( $post->post_type !== 'book' ) {
        return;
    }
    delete_transient( 'book_list_' . $post_id );
}, 10, 2 );

PHP save_post · Hook 1 of 2 · Step 1 of 7

Practice the save_post WordPress action hook in our interactive sandbox — a VS Code-style editor with a step-by-step save_post tutorial, add_action exercises, and instant feedback. No local WordPress install required.