Intermediate Topic 22 of 51 Web Development
Local Storage and Cookies
Browser mechanisms for persisting small data.
How it works
localStorage and sessionStorage hold strings per origin (about 5 MB); cookies are sent with every request and can be HttpOnly, Secure and SameSite.
Where it is used
Preferences, sessions.
Common pitfall
Never store secrets or tokens in localStorage where XSS can read them.
Where it fits in the course
Local Storage and Cookies is topic 22 of 51 in Web Development, rated Intermediate. It follows ES Modules. The next topic is CSS Animations.
Practice and explore
- Open the interactive lesson, with a mini quiz.
- Take the Web Development quiz.
How to study this topic
- Read the explanation above and restate the definition in your own words.
- Open the interactive lesson and answer its mini quiz.
- Read the common pitfall, then write a short example that avoids it.
- Check your understanding in the Web Development quiz, and revisit the topic if you miss a question.
Frequently asked questions
What is Local Storage and Cookies?
Browser mechanisms for persisting small data. It belongs to Web Development and is an intermediate-level topic.
Where do people use Local Storage and Cookies?
Preferences, sessions.
What is the most common mistake with Local Storage and Cookies?
Never store secrets or tokens in localStorage where XSS can read them.
What should I learn before this topic?
Start with ES Modules, the topic just before it in Web Development.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Web Development quiz.
Is Local Storage and Cookies hard to learn?
It is an Intermediate topic. Be comfortable with the Beginner topics in this area first, then read the common pitfall carefully, since it is where most mistakes happen.
How long does it take to learn Local Storage and Cookies?
Most learners can read the explanation and finish the interactive lesson in under an hour. Fluency comes from applying the idea, so plan a few short practice sessions with the quiz.
Which topics are related to Local Storage and Cookies?
ES Modules, CSS Animations, Event Loop are closely connected. The full list is in the related topics section of this page.
What should I study after Local Storage and Cookies?
Continue with CSS Animations, the next topic in Web Development.
Related topics
- ES Modules (Web Development)
- CSS Animations (Web Development)
- Event Loop (Web Development)
- Web Accessibility (Web Development)
- Mobile Storage (Mobile, Embedded & IoT)
- Object Storage (Distributed Systems & Cloud)
- Storage Devices (Computer Architecture & Logic)