# Bad value “Expires” for attribute “http-equiv” on element “meta”.
> Canonical HTML version: https://rocketvalidator.com/html-validation/bad-value-expires-for-attribute-http-equiv-on-element-meta
> Attribution: Rocket Validator (https://rocketvalidator.com)
> License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
The `http-equiv` attribute on the `` element is designed to simulate certain HTTP response headers directly in HTML. However, the HTML specification only permits a specific set of values: `content-type`, `default-style`, `refresh`, `x-ua-compatible`, and `content-security-policy`. Using `Expires` as a value for `http-equiv` will trigger a validation error because it falls outside this permitted set.
Historically, some older browsers and HTML versions were more lenient about which values could appear in `http-equiv`, and developers commonly used `` or similar patterns to try to prevent page caching. However, this approach was never reliable — browsers and caching proxies handle actual HTTP headers far more consistently than `` tag equivalents. Modern HTML formally disallows this value.
Beyond standards compliance, there are practical reasons to avoid this pattern. Many browsers simply ignore unrecognized `http-equiv` values, meaning the tag does nothing useful. Cache behavior is best controlled at the HTTP level, where servers, CDNs, and proxies all read and respect the headers. Relying on a `` tag for caching gives a false sense of control while cluttering your markup with invalid code.
To fix this issue, remove the `` tag from your HTML and configure the `Expires` or `Cache-Control` HTTP header on your web server.
## Examples
### Incorrect: Using `Expires` in `http-equiv`
This triggers the validation error:
```html
My Page
```
### Correct: Remove the invalid `` tag
Simply remove the offending tag. Only use valid `http-equiv` values:
```html
My Page
```
### Correct: Valid uses of `http-equiv`
For reference, here are examples of valid `http-equiv` values:
```html
My Page
```
### Correct: Set cache expiration via server configuration
The proper way to control caching is through HTTP response headers configured on your server.
**Apache** (`.htaccess` or server config):
```apache
ExpiresActive On
ExpiresByType text/html "access plus 1 day"
```
Or using `Cache-Control` with `mod_headers`:
```apache
Header set Cache-Control "no-cache, no-store, must-revalidate"
Header set Expires "0"
```
**Nginx**:
```nginx
location ~* \.html$ {
expires 1d;
add_header Cache-Control "public, no-transform";
}
```
To prevent caching entirely in Nginx:
```nginx
location ~* \.html$ {
expires -1;
add_header Cache-Control "no-store, no-cache, must-revalidate";
}
```
If you don't have access to server configuration, many server-side languages let you set headers programmatically. For example, in PHP:
```php
```
By handling cache expiration at the server level, you get reliable behavior across all browsers, proxies, and CDNs — while keeping your HTML clean and standards-compliant.