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There are a number of things you can do to help secure your site. This article offers an assortment of suggestions, as well as links to other articles providing more useful information.

Note: This article is a work in progress, and is neither complete nor does following its suggestions guarantee your site will be fully secure.

User information security

How to turn off form autocompletion
Form fields support autocompletion in Gecko; that is, their values can be remembered and automatically brought back the next time the user visits your site. For certain types of data, you may wish to disable this feature.
Privacy and the :visited selector
This article discusses changes made to the getComputedStyle() method that eliminates the ability for malicious sites to figure out the user's browsing history.
Hash passwords using a secure algorithm (OWASP)
Storing passwords in plain text can lead to attackers knowing and leaking the exact password of your site's users, potentially putting the users at risk. The same issues can arise if you use an old or insecure algorithm for hashing (such as md5). You should use a password-specific hashing algorithm (such as Argon2, PBKDF2, scrypt or bcrypt) instead of message digest algorithms (such as md5 and sha). This article showcases best practices to use when storing passwords.

Content security

Properly configuring server MIME types
There are several ways incorrect MIME types can cause potential security problems with your site. This article explains some of those and shows how to configure your server to serve files with the correct MIME types.
HTTP Strict Transport Security
The Strict-Transport-Security: HTTP header lets a website specify that it may only be accessed using HTTPS.
HTTP access control
The Cross-Origin Resource Sharing standard provides a way to specify what content may be loaded from other domains. You can use this to prevent your site from being used improperly; in addition, you can use it to establish resources that other sites are expressly permitted to use.
Content Security Policy
An added layer of security that helps to detect and mitigate certain types of attacks, including Cross Site Scripting (XSS) and data injection attacks. These attacks are used for everything from data theft to site defacement or distribution of malware.
The X-Frame-Options response header

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>. Sites can use this to avoid clickjacking attacks, by ensuring that their content is not embedded into other sites.

Securing Your Site using Htaccess
Learn the best way and almost all the tricks to secure your site using the .htaccess file. You can blacklist IPs, restrict access to certain areas of website, protect different files, protect against image hotlinking, and a lot more.

See also

Document Tags and Contributors

 Contributors to this page: mbm, chrisdavidmills, JazibZaman, hashedhyphen, marumari, evilpie, Sheppy, teoli
 Last updated by: mbm,