How to Set Cache-Control Header in Nginx for Efficient Caching

To set the cache-control header in Nginx, use the add_header Cache-Control directive inside a server, location, or http block. This header controls how browsers cache your content, improving load times and reducing server load.

Syntax

The add_header directive sets HTTP headers in Nginx responses. To set the cache-control header, use:

• add_header Cache-Control "value"; — sets the cache-control header with the specified value.
• Place it inside http, server, or location blocks depending on scope.
• Common values include no-cache, no-store, max-age=seconds, and public.

nginx

add_header Cache-Control "max-age=3600, public";

Example

This example shows how to set the cache-control header to cache static files for 1 hour in a specific location.

nginx

server {
    listen 80;
    server_name example.com;

    location /static/ {
        root /var/www/html;
        add_header Cache-Control "max-age=3600, public";
    }
}

Output

When a client requests a file under /static/, the response includes the header:
Cache-Control: max-age=3600, public

Common Pitfalls

• Not placing add_header inside the correct block can cause headers to not be sent.
• Using add_header with if blocks incorrectly may prevent headers from applying.
• Remember that add_header only works on successful responses (status 200, 204, 301, 302, 304). For other statuses, use add_header ... always; in newer Nginx versions.

nginx

location / {
    # Wrong: header won't be added on error responses
    add_header Cache-Control "no-cache";
}

location / {
    # Correct: header added always
    add_header Cache-Control "no-cache" always;
}

Quick Reference

Directive	Description	Example Value
add_header Cache-Control	Sets cache-control header	"max-age=3600, public"
max-age	Time in seconds to cache	3600
no-cache	Forces revalidation	no-cache
no-store	Prevents caching	no-store
public	Marks response as cacheable by any cache	public
private	Marks response as cacheable only by browser	private
must-revalidate	Forces cache to revalidate after expiry	must-revalidate

Key Takeaways

Use add_header Cache-Control "value"; inside http, server, or location blocks to set caching rules.

Common cache-control values include max-age, no-cache, no-store, public, and private.

Add always to add_header to ensure headers are sent on all response codes.

Place the directive carefully to apply caching only where needed, such as static files.

Test your configuration by checking response headers with browser DevTools or curl.