How to Set Expires Header in Nginx for Cache Control

To set the expires header in Nginx, use the expires directive inside a location or server block. This directive controls how long browsers cache static files by specifying a time duration or a date.

Syntax

The expires directive sets the caching time for responses. It accepts values like off, epoch, max, or a time duration such as 30d (30 days), 1h (1 hour), etc.

Example parts:

• expires 30d; — cache for 30 days
• expires off; — disable caching
• expires max; — cache for maximum time (about 10 years)

nginx

location /images/ {
    expires 30d;
}

Example

This example sets the expires header to 7 days for all files in the /static/ folder. Browsers will cache these files for one week, reducing server load and speeding up page loads.

nginx

server {
    listen 80;
    server_name example.com;

    location /static/ {
        root /var/www/html;
        expires 7d;
    }
}

Output

When a browser requests a file under /static/, the response header will include: Expires: <date 7 days in the future>

Common Pitfalls

Common mistakes when setting the expires header include:

• Placing the expires directive outside a location or server block, which causes errors.
• Using incorrect time formats like 30days instead of 30d.
• Not reloading Nginx after changes, so the new settings don't apply.
• Setting very long cache times for files that change often, causing stale content.

nginx

location /assets/ {
    expires 30days;  # Incorrect, should be 30d
}

# Correct:
location /assets/ {
    expires 30d;
}

Quick Reference

Directive	Meaning	Example
expires off;	Disable caching	expires off;
expires epoch;	Set expiry to 1 Jan 1970 (immediate expiry)	expires epoch;
expires max;	Set expiry to maximum (about 10 years)	expires max;
expires 1h;	Cache for 1 hour	expires 1h;
expires 30d;	Cache for 30 days	expires 30d;

Key Takeaways

Use the expires directive inside location or server blocks to control caching.

Specify cache duration with time units like d for days or h for hours (e.g., expires 7d;).

Avoid very long cache times for frequently updated files to prevent stale content.

Always reload Nginx after changing configuration to apply new settings.

Use expires off; to disable caching when needed.