PHP file upload exceeds upload_max_filesize

1. About the error
2. Why do I see this error
3. Solution
4. Don't forget the layers in front of PHP

#About the error

Unlike most errors, this one is quiet. The upload just doesn't arrive, $_FILES is empty, or you see UPLOAD_ERR_INI_SIZE in the file's error key. PHP discarded the file before your code ever ran.

This is distinct from, but often confused with, the 413 Request Entity Too Large error. That one is nginx rejecting the request before it reaches PHP. If you've already raised nginx's client_max_body_size and uploads still fail, PHP's own limits are the next place to look.

#Why do I see this error

Two PHP settings cap upload size, and the lower of the two wins:

• upload_max_filesize, the maximum size of a single uploaded file.
• post_max_size, the maximum size of the entire POST body (which must be larger than upload_max_filesize, with room for other fields).

If either is smaller than the file, PHP drops it.

#Solution

Raise both values in your php.ini. post_max_size should be a bit larger than upload_max_filesize:

upload_max_filesize = 100M
post_max_size = 110M

While you're there, check these related limits don't cut a large upload short:

max_file_uploads = 20
max_execution_time = 120
memory_limit = 256M

Reload PHP-FPM so the changes take effect:

systemctl reload php8.3-fpm

#Don't forget the layers in front of PHP

A large upload has to pass through every layer to succeed. All of these must be big enough:

• nginx, via client_max_body_size, see 413 Request Entity Too Large.
• PHP, via upload_max_filesize and post_max_size above.
• Your application's own validation, for example a Laravel max: rule on the file.

Verify the active PHP values with:

php -i | grep -E 'upload_max_filesize|post_max_size'

Note that the CLI and the FPM SAPI can use different php.ini files, so check the FPM one (/etc/php/8.3/fpm/php.ini) for web uploads.