Nginx 413 Request Entity Too Large

I‘m running nginx as a frond end to php based Apache+mod_fastcgi server. My app lets user upload images upto 2MB in size. When users trying to upload 1.5MB+ size image file using nginx reverse proxy, they are getting the following error on screen:
Nginx 413 Request Entity Too Large

How do I fix this problem and allow image upload upto 2MB in size using nginx web-server working in reverse proxy or stand-alone mode on Unix like operating systems?

The error “413 – Request Entity Too Large” indicates that web server configured to restrict large file size. Nginx can be set to allow the maximum size of the client request body using client_max_body_size directive. If the size of a request exceeds the configured value, the 413 (Request Entity Too Large) error returned to the client. You will see an error as follows:

You need to configure both nginx and php to allow upload size.

Nginx configuration

To fix this issue edit your nginx.conf. Open the Terminal or login to the remote server using ssh client. Type the following command to edit your nginx.conf using a text editor such as vi or joe or nano:

# vi /etc/nginx/nginx.conf

Use nano text editor:

$ sudo nano /etc/nginx/nginx.conf

Must be run as root:

# vi /usr/local/nginx/conf/nginx.conf

Add the following line to http or server or location context to increase the size limit in nginx.conf, enter:

# set client body size to 2M #
client_max_body_size 2M;

The client_max_body_size directive assigns the maximum accepted body size of client request, indicated by the line Content-Length in the header of request. If size is greater the given one, then the client gets the error “Request Entity Too Large” (413).
Save and close the file. Reload the nginx webserver, enter:

# /usr/local/nginx/sbin/nginx -s reload

Use nginx itself to reload it:

# /sbin/nginx -s reload

For RHEL/CentOS/Debian/Ubuntu Linux, try:

# service nginx reload

If you are using systemd based system run:

$ sudo systemctl reload nginx.service

PHP configuration (optional)

Your php installation also put limits on upload file size. Edit php.ini and set the following directives

;This sets the maximum amount of memory in bytes that a script is allowed to allocate
memory_limit = 32M

;The maximum size of an uploaded file.
upload_max_filesize = 2M

;Sets max size of post data allowed. This setting also affects file upload. To upload large files, this value must be larger than upload_max_filesize
post_max_size = 3M

If you are using PHP-FPM, restart it as follows:

$ sudo systemctl restart php-fpm
## OR ##
$ sudo systemctl restart php7.0-fpm.service
## OR ##
$ sudo /usr/local/etc/rc.d/php-fpm restart

Save and close the file. Make sure you reload/restart back-end apache or nginx web server as per your setup. See “PHP Increase Upload File Size Limit” tutorial for more information.

Look out for permission errors too

Apart from setting Nginx and PHP, you need to look out file permission errors. Usually logged into your web server error.log file. Here is a sample error logged in to my lighttpd web server:

2017-07-18 07:09:18: (connections.c.1095) denying upload as opening to temp-file for upload failed: /var/cache/lighttpd/uploads/lighttpd-upload-9UMUXj Permission denied 
2017-07-18 07:23:45: (connections.c.1095) denying upload as opening to temp-file for upload failed: /var/cache/lighttpd/uploads/lighttpd-upload-a4PNg1 Permission denied 
2017-07-18 07:25:50: (connections.c.1095) denying upload as opening to temp-file for upload failed: /var/cache/lighttpd/uploads/lighttpd-upload-xIzdjU Permission denied 
2017-07-18 07:27:30: (connections.c.1095) denying upload as opening to temp-file for upload failed: /var/cache/lighttpd/uploads/lighttpd-upload-2s3I9J Permission denied 
2017-07-18 07:29:04: (connections.c.1095) denying upload as opening to temp-file for upload failed: /var/cache/lighttpd/uploads/lighttpd-upload-9KNsVa Permission denied 
2017-07-18 07:30:19: (connections.c.1095) denying upload as opening to temp-file for upload failed: /var/cache/lighttpd/uploads/lighttpd-upload-myoWrl Permission denied

To fix this you need to setup correct permission using the chmod command or chown command:

$ sudo chown -R lighttpd:lighttpd /var/cache/lighttpd/