Fix WordPress "Upload Failed" or "HTTP Error" on Media Upload

The WordPress "HTTP Error" or "Upload Failed" message when trying to upload images is one of the vaguest error messages in WordPress. It can mean a dozen different things. Here is how to diagnose which cause applies to your situation and fix it.

Identify the specific error

The generic "HTTP Error" hides the real cause. Before applying fixes, get more detail:

Enable WP_DEBUG temporarily:

In wp-config.php:

define( 'WP_DEBUG',         true );
define( 'WP_DEBUG_LOG',     true );
define( 'WP_DEBUG_DISPLAY', false ); // don't show errors to visitors

Try the upload again. Then check wp-content/debug.log for the specific PHP error.

Check browser console: Open DevTools > Network tab, then attempt the upload. Look for the XHR request to async-upload.php. Check its response for an error message.

Check server error log:

tail -n 50 /var/log/nginx/yourdomain.com.error.log
# or for Apache:
tail -n 50 /var/log/apache2/error.log

Cause 1 - File size too large

The most common cause for large images: the upload exceeds PHP's upload_max_filesize or post_max_size limits.

Check current limits: Add this temporarily to any page template to see the current limits:

<?php
echo ini_get('upload_max_filesize') . '<br>';
echo ini_get('post_max_size') . '<br>';
echo ini_get('memory_limit');

Or check via WP-CLI:

wp eval 'echo ini_get("upload_max_filesize");'

Fix via php.ini:

upload_max_filesize = 64M
post_max_size = 64M
memory_limit = 256M

Location of php.ini varies by server setup:

• /etc/php/8.3/fpm/php.ini (PHP-FPM on Ubuntu)
• /etc/php.ini (CentOS/AlmaLinux)
• /usr/local/lib/php.ini (some control panels)

After editing, restart PHP-FPM:

sudo systemctl restart php8.3-fpm

Fix via wp-config.php:

@ini_set( 'upload_max_size', '64M' );
@ini_set( 'post_max_size',   '64M' );
@ini_set( 'memory_limit',    '256M' );

Fix via .htaccess (Apache only):

php_value upload_max_filesize 64M
php_value post_max_size 64M
php_value memory_limit 256M

Fix in WordPress functions.php: WordPress also has its own upload size filter:

add_filter( 'upload_size_limit', function() {
    return 64 * MB_IN_BYTES; // 64MB
});

Note: post_max_size must be larger than upload_max_filesize. If upload_max_filesize is 64M but post_max_size is still 8M (the default), the upload still fails.

Cause 2 - PHP memory exhausted

Large image files require PHP memory to process (resize, create thumbnails). If memory_limit is too low:

# Check if this is the error in debug.log
grep "Allowed memory size" /var/www/html/wp-content/debug.log

Fix:

// wp-config.php
define( 'WP_MEMORY_LIMIT', '256M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );

And in php.ini:

memory_limit = 256M

Cause 3 - File permission error

WordPress needs write permission to the uploads directory. If the web server process cannot write to wp-content/uploads/, every upload fails.

Check permissions:

ls -la /var/www/html/wp-content/

The uploads directory should be owned by the web server user (typically www-data) and have 755 permissions:

sudo chown -R www-data:www-data /var/www/html/wp-content/uploads
sudo chmod -R 755 /var/www/html/wp-content/uploads

Check if the uploads directory exists:

ls /var/www/html/wp-content/uploads

If it does not exist:

sudo mkdir -p /var/www/html/wp-content/uploads
sudo chown www-data:www-data /var/www/html/wp-content/uploads
sudo chmod 755 /var/www/html/wp-content/uploads

Cause 4 - Image editor library problem

WordPress uses either GD Library or ImageMagick to process uploaded images (create thumbnails, resize). If the active library has a bug with a particular image format or is misconfigured:

Check which library is active: Go to Tools > Site Health > Info > Media Handling. This shows which image editor is in use and which formats are supported.

Switch between GD and ImageMagick:

To force GD:

add_filter( 'wp_image_editors', function( $editors ) {
    return [ 'WP_Image_Editor_GD', 'WP_Image_Editor_Imagick' ];
});

To force ImageMagick:

add_filter( 'wp_image_editors', function( $editors ) {
    return [ 'WP_Image_Editor_Imagick', 'WP_Image_Editor_GD' ];
});

Add to functions.php, test the upload, then remove the code if GD works but ImageMagick does not (or report the issue to your host).

Install missing PHP extensions:

sudo apt-get install -y php8.3-imagick php8.3-gd
sudo systemctl restart php8.3-fpm

Cause 5 - Security plugin blocking the upload

Some security plugins (Wordfence, WP Cerber) have file type restrictions that block uploads of certain file types, or rate-limit upload requests.

Test:

1. Temporarily deactivate your security plugin
2. Attempt the upload
3. If it works: the security plugin has a setting causing it

In Wordfence: check "Firewall" settings for file upload restrictions. Wordfence has a "Block upload of PHP files and other executable files" setting that occasionally misidentifies safe files.

Cause 6 - Wrong file type

WordPress has an allowed file types list. By default, it blocks PHP files (for security) and some less-common formats.

If you are trying to upload an SVG, PDF, or other non-default type:

// Add SVG support
add_filter( 'upload_mimes', function( $mime_types ) {
    $mime_types['svg']  = 'image/svg+xml';
    $mime_types['svgz'] = 'image/svg+xml';
    return $mime_types;
});

// Add MIME type check
add_filter( 'wp_check_filetype_and_ext', function( $data, $file, $filename, $mimes ) {
    $ext     = pathinfo( $filename, PATHINFO_EXTENSION );
    $type    = false;
    $proper  = false;

    if ( 'svg' === $ext ) {
        $type   = 'image/svg+xml';
        $proper = 'svg';
    }

    if ( $type ) {
        $data['ext']  = $proper;
        $data['type'] = $type;
    }

    return $data;
}, 10, 4 );

Security note for SVG: SVG files can contain embedded JavaScript and present an XSS risk if uploaded by untrusted users. Only allow SVG uploads if you control who uploads them (authors/admins you trust). Use the Safe SVG plugin for sanitisation.

Quick fix checklist

• [ ] Enable WP_DEBUG_LOG and check the actual error in debug.log
• [ ] Verify upload_max_filesize and post_max_size are at least 64M
• [ ] Verify memory_limit is at least 256M
• [ ] Check uploads directory permissions (www-data owned, 755)
• [ ] Switch image editor from ImageMagick to GD or vice versa
• [ ] Temporarily deactivate security plugin to test
• [ ] Check file type is in the allowed MIME list

Related reading

• Fix WordPress PHP Memory Exhausted Error
• WordPress wp-config.php Tweaks
• Fix WordPress White Screen of Death