WordPress Multisite: How to Change File Upload Types and Size Limits

WordPress Multisite Network: How to Modify File Upload Types and Size Limits

After enabling WordPress Multisite mode, the default file upload size may be restricted to a low value (e.g., 1MB). This guide explains how to modify allowed file types and size limits in a multisite network.

Modify via Network Admin Dashboard

Log into your WordPress admin dashboard and navigate to: My Sites → Network Admin → Settings. Scroll to the bottom of the page to find the "Upload Settings" section. Here you can directly adjust:

• Upload File Types: List of allowed file extensions (separated by spaces).
• Site Upload Space: Total storage space available per site.
• Max Upload File Size: Maximum allowed size for a single file.

Adjust the values according to your needs and save the changes.

Important Considerations

The value set for "Max Upload File Size" is also subject to server PHP configuration limits. For example:

• Many web hosting providers impose server‑level limits on single‑file upload size (e.g., max 10MB). Even if you set 20MB in WordPress, the server limit (10MB) will still apply.
• If you have server administration access, you need to modify the following parameters in the PHP configuration file (usually php.ini):

  upload_max_filesize = 64M
  post_max_size = 64M

  After making changes, restart your web service (e.g., Apache or Nginx) for the new settings to take effect.

Tip: For multisite networks, you may sometimes also need to add or modify definitions in the wp-config.php file to override defaults, e.g., define('WP_MAX_MEMORY_LIMIT', '256M');. It is recommended to back up relevant files before making changes.

Summary Steps

1. Log into your WordPress multisite network admin dashboard.
2. Go to the "Settings" page and modify the upload limits.
3. Verify that your server PHP configuration (upload_max_filesize and post_max_size) supports your settings.
4. If necessary, add memory or file‑size definitions in wp-config.php.
5. Clear site cache and test the file upload functionality.