Save data in the browser.
✍️ 3 exercises + code challenge in this lessonThe Web Storage API saves small amounts of data in the user's browser.
localStorage: kept even after the browser is closed.sessionStorage: cleared when the tab is closed.Methods: setItem(key, value), getItem(key), removeItem(key), clear(). Values are always strings, so use JSON.stringify / JSON.parse for objects.
Mastering JavaScript Local Storage helps you write clean and reliable JavaScript code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.
<p>Visits counted in this browser: <strong id="visits">?</strong></p>
<button onclick="location.reload()">Reload</button>
<button onclick="reset()">Reset</button>
<script>
let visits = 0;
try {
visits = Number(localStorage.getItem("visits") || 0) + 1;
localStorage.setItem("visits", visits);
} catch (e) {
visits = "storage blocked in this frame";
}
document.getElementById("visits").textContent = visits;
function reset() {
try { localStorage.removeItem("visits"); } catch (e) {}
location.reload();
}
</script>Check what you learned in “JavaScript Local Storage”.
Save a value in the browser.
localStorage.("theme", "dark");
What type of values does localStorage store?
Convert the object to a JSON string with JSON.stringify and log it.
Free sign-in required · Google login available
Stuck on something?
Ask the community in the CodesInTech forum.
Need a developer?
Learning on your own is great — and when you need professional help, our team builds custom software, websites and mobile apps for clients worldwide.
Explore Our Services