How To Increase File Upload Size in Nginx Web Server

In this article, we will demonstrate how to limit file upload size in Nginx. One of the most common errors system admins encounter is when users complain that their file upload couldn’t complete. The error associated with this issue is client intended to send too large body and can be found in /var/log/nginx/error.log.

Apart from the need to increase the file upload size, webmasters or sysadmins need to restrict the file upload size to prevent some types of denial-of-service (DOS) attacks.

By default, Nginx has a limit of 1MB for file uploads. The directive responsible for this is the client_max_body_size which is part of the Nginx’s ngx_http_core_module.

In order to change the default 1MB limit, you need to use the directive in /etc/nginx/nginx.conf file as follows:

1. Set in http block (affects all virtual hosts)

http {
    ...
   
 client_max_body_size 100M;
}  

2. Set in server block (affects a particular virtual host)

server {
    ...
 
   client_max_body_size 100M;
}

3. Set in php block (affects all php files within a site/app)

location ~ \.php$ { 
    ...
  
    client_max_body_size 100M;
} 

Once you do the necessary changes, save the nginx.conf file and restart the Nginx web server to apply the changes, as follows:

nginx -t // dry-run to ensure no syntax errors exist

systemctl restart nginx // restart to apply the saved changes