Nginx Request Entity Too Large

The HTTP 413 error occurs when a client (e.g., a browser) sends a request body (like a file upload) that exceeds the limit defined by the `client_max_body_size` directive in the Nginx configuration.

Common Causes

Uploading a file larger than the default or configured `client_max_body_size` limit (default is often 1MB).
Misconfigured or missing `client_max_body_size` directive in the relevant server or location block.
A large POST request payload from an API client or web application.
Inherited limit from a parent configuration block that is too restrictive.

How to Fix

1 Increase client_max_body_size in Nginx Config

Set or increase the `client_max_body_size` directive in the appropriate server or location block (e.g., for uploads).

BASH

 $ server {
    # ...
    client_max_body_size 20M;
    # ...
}

2 Apply Limit to Specific Location

Apply a larger size limit specifically to an upload endpoint or location.

BASH

 $ location /upload {
    client_max_body_size 100M;
    # ... proxy_pass or other directives
}

3 Test Configuration and Reload Nginx

After editing the configuration file, test for syntax errors and reload Nginx to apply changes.

BASH

 $ sudo nginx -t
sudo systemctl reload nginx  # or sudo nginx -s reload