Browser Terms Explained: SameSite cookies

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Browser Terms Explained: SameSite cookies

Get SigmaOS Free

It's free and super easy to set up

Browser Terms Explained: SameSite cookies

Get SigmaOS Free

It's free and super easy to set up

Browser Terms Explained: SameSite cookies

When browsing the internet, you've probably come across cookies before. They are small pieces of data stored by websites on your device to remember your preferences or track your activity. However, not all cookies are created equal. Some are more secure than others, and SameSite cookies fall into this category.

Understanding Browser Cookies

Before diving into SameSite cookies, let's first explore what cookies are and how they work.

Cookies are small text files that websites place on your computer or mobile device when you visit them. They are designed to hold a modest amount of data specific to a particular client and website and can be accessed either by the web server or the client computer. Cookies are typically used to keep track of a user's preferences, login information, and browsing behavior.

When you visit a website, it sends a request for data to a server. In response, the server sends back information about the website, including any cookies it has stored on your device. The browser then stores these cookies on your device, and the site can later read them to customize content or remember your preferences.

How Cookies Work

When a website wants to set a cookie, it sends a response header to the browser with a "Set-Cookie" instruction. This instruction contains a small piece of text that the browser stores on the user's device. The next time the user visits the website, the browser sends the cookie back to the server, allowing the website to recognize the user and remember their preferences.

Cookies can be either session-based, meaning they are deleted when the browser is closed, or they can be persistent, meaning they stay on your computer until they expire or are deleted manually. Persistent cookies are used to remember user preferences and login information over a longer period of time.

Types of Cookies

There are several types of cookies, including:

  • Essential Cookies: These are necessary for a website to function properly and are typically set in response to user actions such as logging in or filling out forms. Without these cookies, the website may not be able to provide certain features or services.

  • Functional Cookies: These cookies help enhance the usability of a website by remembering user preferences, such as language or currency selection. They improve the user experience by making the website more personalized and user-friendly.

  • Analytics Cookies: These track user behavior on a website to provide insights on how to improve the user experience. They collect data on how users interact with a website, such as which pages they visit and how long they stay on each page.

  • Advertising Cookies: These cookies are used to deliver targeted advertisements to users based on their browsing history and preferences. They collect data on a user's browsing behavior and use it to show personalized ads that are more relevant to the user's interests.

Cookies are an essential part of the modern web, allowing websites to provide personalized experiences and remember user preferences. However, they can also be used to track user behavior and collect sensitive information, so it's important to be aware of how they work and to take steps to protect your privacy online.

The Importance of SameSite Cookies

SameSite cookies are essential for improving the security and privacy of web browsing. They restrict cookie access to first-party connections, preventing unauthorized third-party access to user data. But there's more to SameSite cookies than just that.

Enhancing Security

One of the most critical benefits of SameSite cookies is their ability to enhance website and user security. By restricting cookie access, SameSite cookies help prevent cross-site scripting attacks, where attackers inject malicious scripts into legitimate websites and hijack user sessions.

For example, imagine that you're browsing a website that has a vulnerability that allows attackers to inject malicious scripts. Without SameSite cookies, the attacker could potentially steal your login credentials or other sensitive information. However, with SameSite cookies, the attacker's access to your cookies would be restricted, preventing them from accessing your data.

Preventing Cross-Site Request Forgery (CSRF) Attacks

SameSite cookies also help prevent cross-site request forgery (CSRF) attacks, a type of attack where a user is tricked into submitting an unwanted action on a website without their knowledge or consent. SameSite cookies help protect users by ensuring that cookies from one site cannot be used to submit unwanted actions on another site.

For example, imagine that you're logged into your bank's website and another website you visit has a hidden form that submits a transfer request to your bank without your knowledge. Without SameSite cookies, the other website could potentially use your bank's cookies to authenticate the transfer request. However, with SameSite cookies, the other website's cookies would be restricted, preventing the transfer request from being authenticated.

Improving User Privacy

SameSite cookies help improve user privacy by preventing third-party websites from accessing user data and tracking their online behavior. This enhances user trust and confidence in web browsing experiences.

For example, imagine that you're browsing a website that has third-party ads. Without SameSite cookies, the third-party ad providers could potentially track your online behavior and build a profile of your interests and preferences. However, with SameSite cookies, the ad providers' cookies would be restricted, preventing them from tracking your behavior and invading your privacy.

Overall, SameSite cookies are an essential tool for improving web browsing security and privacy. By restricting cookie access and preventing unauthorized access to user data, SameSite cookies help protect users and enhance their browsing experiences.

SameSite Cookie Attributes

There are three different types of SameSite cookie attributes:


This attribute is the default value and allows cookies to be sent in cross-site requests. However, this presents a potential security risk and is not recommended unless the cookie is protected by Secure attributes.


This attribute restricts cookie access to first-party connections and allows cookies to be sent in certain cross-site requests, such as when following a hyperlink. This helps mitigate attacks such as CSRF and enhances website and user security.


This attribute completely restricts cookie access to third-party connections and only allows cookies to be sent in first-party requests. This provides the highest level of security and privacy protection for users.

Implementing SameSite Cookies

Now that we've covered the importance and attributes of SameSite cookies, let's explore how to implement them.

Setting SameSite Attributes in Different Browsers

Implementing SameSite cookies is straightforward and involves setting the SameSite attribute to either Lax or Strict. The exact method for setting this attribute varies depending on the browser. Below are instructions for setting SameSite attributes in different browsers:

  • Chrome: Add "SameSite=Strict" or "SameSite=Lax" to the cookie using document.cookie.

  • Firefox: Add "SameSite=Strict" or "SameSite=Lax" to the cookie header using Set-Cookie.

  • Safari: Add "SameSite=Strict" or "SameSite=Lax" to the cookie header using Set-Cookie.

  • Edge: Add "SameSite=Strict" or "SameSite=Lax" to the cookie header using Set-Cookie.

Common Issues and Solutions

When implementing SameSite cookies, there are a few common issues you may encounter. For example, if you set SameSite as "Strict" and then access a cookie from a cross-site subdomain, the cookie will not be sent. To solve this issue, set the cookie as "Lax" instead.

Best Practices for Developers

Developers can follow the best practices below when implementing SameSite cookies:

  • Use SameSite=Lax as the default setting for cookies.

  • Set SameSite=Strict only when necessary, such as for sensitive information like authentication tokens.

  • Use HTTPS to protect cookies from eavesdropping and other security risks.

  • Perform regular testing and debugging to ensure proper implementation and compatibility with different browsers.


SameSite cookies are an essential part of modern web browsing that enhance security and privacy for users. By restricting cookie access to first-party connections, SameSite cookies help prevent cross-site scripting and CSRF attacks while also limiting third-party tracking. Implementing SameSite cookies is relatively straightforward and follows specific best practices. By properly implementing SameSite cookies, developers can provide their users with a secure and private browsing experience.