What is a session cookie?
A session cookie is a temporary piece of data that websites use to remember you during a single visit. It starts when you open a website and ends when you close your browser or log out. Think of it like a claim ticket at a coat check - it identifies you while you're there, but becomes useless once you leave.
Unlike persistent cookies that stick around on your hard drive, session cookies live in your browser's temporary memory. When you close the browser, they disappear completely. This temporary nature makes them less invasive from a privacy perspective while still letting websites function properly.
How session cookies work
When you visit a website, the server creates a unique session ID - basically a random number that serves as your temporary identifier. Your browser stores this ID in a session cookie and automatically sends it back to the server with every request you make on that site.
Here's the important part: the cookie itself doesn't contain your personal information. It only holds that ID number. All your actual data - like items in your shopping cart or your login status - stays on the website's server. The cookie just tells the server which data belongs to you.
This setup works because HTTP (the protocol that powers the web) has no memory. Without session cookies, every page you visit would treat you as a brand new visitor. You'd have to log in again on every page, and your shopping cart would empty each time you clicked a link.
Common uses for session cookies
Session cookies power several critical website features:
Login sessions: When you log into a website, a session cookie keeps you logged in as you browse different pages. Close your browser, and you'll need to log in again next time.
Shopping carts: E-commerce sites use session cookies to remember what you've added to your cart as you browse products. Without them, your cart would reset on every page.
Multi-page forms: Websites with long forms spread across multiple pages use session cookies to remember your answers as you progress through each step.
Live chat persistence: When you're chatting with customer service, session cookies maintain that conversation as you navigate to different pages to find information.
Session cookies vs. persistent cookies
The key difference comes down to lifespan. Session cookies vanish when you close your browser. Persistent cookies stick around for days, months, or even years - they have a specific expiration date set by the website.
Session cookies live in RAM (temporary memory), while persistent cookies get written to your hard drive. This means session cookies can't track you across multiple visits. Persistent cookies can remember your preferences and recognize you when you return to a site days later.
From a privacy standpoint, session cookies generally don't require consent under GDPR because they're considered essential for basic website functionality. Persistent cookies, especially those used for tracking and analytics, typically do require consent.
Session cookies in web scraping
When you're scraping websites, session cookies become critical for maintaining access and context. Many websites require login before showing content. When your scraper logs in, it receives a session cookie. You need to capture that cookie and send it with every subsequent request, or the website will treat each request as coming from an unauthenticated user.
Websites that use multi-step processes - like checkout flows, form submissions, or paginated data - rely on session cookies to maintain state. If your scraper doesn't properly handle session cookies, these processes will fail because the website can't connect your requests together.
The temporary nature of session cookies also affects scraping strategies. If your scraper runs for longer than the session timeout period (often 20-30 minutes of inactivity), the session cookie expires. Your scraper needs to detect this and re-authenticate to get a new session cookie, or it will start receiving error pages instead of data.
Security features on session cookies can also impact scrapers. Many sites set the HttpOnly flag, which prevents JavaScript from accessing the cookie. They might also use the Secure flag, requiring HTTPS connections. Your scraping tool needs to respect these security measures and handle cookies exactly as a legitimate browser would.
How Browse AI handles session cookies
When you're building scrapers that need to handle logins or maintain session state, managing cookies manually can get complicated. Browse AI automatically handles session cookie management for you. The platform maintains sessions across multiple page visits, handles re-authentication when sessions expire, and ensures your scrapers behave like legitimate browsers. This means you can extract data from authenticated areas without writing custom cookie management code or worrying about session timeouts breaking your scraping workflows.
