I am trying to use wp_redirect() to redirect the user after successfully submitting a signup form on the page.

It's not working and shows the following error:

Warning: Cannot modify header information - headers already sent by (output started at /Applications/MAMP/htdocs/theme/wp-content/themes/test/header.php:10) in /Applications/MAMP/htdocs/theme/wp-includes/pluggable.php on line 1178

I understand there has been already output before, that's why it's not working, but I have no clue how to make this work.

The signup form gets rendered by a function, and is submitted by another function, inside my functions.php.

if ( isset( $_POST['subscribe'] ) ) {
    // Submits the form and should then redirect

Then both these functions are used where I want to show the signup form.

I'm afraid that's not the best thing to do. I should be creating some action that does that, but I have no idea how to implement that. Most of the tutorials I found show the results directly on the same page and don't require an additional redirect. Maybe that's why they are working with functions inside the functions.php

5 Answers 5


Found the answer (via)

Instead of using the function directly, I added an action to "wp_loaded", that makes sure that it gets loaded before any headers are sent.

add_action ('wp_loaded', 'my_custom_redirect');
function my_custom_redirect() {
    if ( isset( $_POST['subscribe'] ) ) {
        $redirect = 'http://example.com/redirect-example-url.html';
  • It got rid of the error but the post did not save! Commented Feb 23, 2017 at 14:24

You have to use wp_redirect() before get_header() Then it will not show header error.


you can also do this

Instead of the below line



echo("<script>location.href = '".$url."'</script>");


<?php <script><?php echo("location.href = '".$url."';");?></script>?>

It'll definitely solve your problem.

  • thanks a lot man ! Commented Oct 24, 2023 at 2:50
  • your welcome...@MarcoFloriano Commented Oct 24, 2023 at 15:58
add_action('template_redirect', function(){
if(isset($_POST['subscriptio'])){// make this condition such that it only matches when a registraiotn form get submitted
 * do your stuff here
  • Thanks for the help, but that code didn't worked for me. Needed to add the action to "wp_loaded" to get it worked (See my answer)
    – Snowball
    Commented Feb 23, 2015 at 12:09
  • Works well if you need to establish is_page_template() when conditionally redirecting. Commented Apr 2, 2020 at 5:09

If you are creating a plugin, you can call ob_start(); at the beginning of the plugin code or ob_start(); at the top of the functions.php file before code begins

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