X-Frame-Options

The X-Frame-Options HTTP response header can be used to indicate whether or not a browser should be allowed to render a page in a <frame>, <iframe>, <embed> or <object>. Sites can use this to avoid click-jacking attacks, by ensuring that their content is not embedded into other sites.

The added security is provided only if the user accessing the document is using a browser that supports X-Frame-Options.

There are two possible directives for X-Frame-Options:

X-Frame-Options: DENY
X-Frame-Options: SAMEORIGIN

If you specify DENY, not only will the browser attempt to load the page in a frame fail when loaded from other sites, attempts to do so will fail when loaded from the same site. On the other hand, if you specify SAMEORIGIN, you can still use the page in a frame as long as the site including it in a frame is the same as the one serving the page.

DENY

The page cannot be displayed in a frame, regardless of the site attempting to do so.

SAMEORIGIN

The page can only be displayed in a frame on the same origin as the page itself. The spec leaves it up to browser vendors to decide whether this option applies to the top level, the parent, or the whole chain, although it is argued that the option is not very useful unless all ancestors are also in the same origin (see bug 725490). Also see Browser compatibility for support details.

ALLOW-FROM uri

This is an obsolete directive that no longer works in modern browsers. Don't use it. In supporting legacy browsers, a page can be displayed in a frame only on the specified origin uri. Note that in the legacy Firefox implementation this still suffered from the same problem as SAMEORIGIN did — it doesn't check the frame ancestors to see if they are in the same origin. The Content-Security-Policy HTTP header has a frame-ancestors directive which you can use instead.

To configure Apache to send the X-Frame-Options header for all pages, add this to your site's configuration:

Header always set X-Frame-Options "SAMEORIGIN"

To configure Apache to set the X-Frame-Options DENY, add this to your site's configuration:

Header set X-Frame-Options "DENY"

To configure Nginx to send the X-Frame-Options header, add this either to your http, server or location configuration:

add_header X-Frame-Options SAMEORIGIN always;

To configure IIS to send the X-Frame-Options header, add this to your site's Web.config file:

<system.webServer>
  ...

  <httpProtocol>
    <customHeaders>
      <add name="X-Frame-Options" value="SAMEORIGIN" />
    </customHeaders>
  </httpProtocol>

  ...
</system.webServer>

Or see this Microsoft support article on setting this configuration using the IIS Manager user interface.

To configure HAProxy to send the X-Frame-Options header, add this to your front-end, listen, or backend configuration:

rspadd X-Frame-Options:\ SAMEORIGIN

Alternatively, in newer versions:

http-response set-header X-Frame-Options SAMEORIGIN

To configure Express to send the X-Frame-Options header, you can use helmet which uses frameguard to set the header. Add this to your server configuration:

const helmet = require('helmet');
const app = express();
app.use(helmet.frameguard({ action: 'SAMEORIGIN' }));

Alternatively, you can use frameguard directly:

const frameguard = require('frameguard')
app.use(frameguard({ action: 'SAMEORIGIN' }))

• Content-Security-Policy directive frame-ancestors
• HTTP Header Field X-Frame-Options - RFC 7034
• ClickJacking Defenses - IEBlog
• Combating ClickJacking with X-Frame-Options - IEInternals