JavaScript Navigator appName Property

What You’ll Learn

navigator.appName is a legacy Navigator property. Per MDN, its value is always "Netscape" in any browser — kept only for compatibility. Learn what it returns, how it pairs with appCodeName, five examples, and better alternatives.

Introduction

In the 1990s, many sites checked the “application name” to decide which scripts to run. Netscape was a common target, so other browsers began reporting the same name. Today that value is frozen as a compatibility string.

Log navigator.appName in Chrome, Edge, Firefox, or Safari and you will see Netscape — not the brand name on the window chrome.

Pair it mentally with appCodeName ("Mozilla"): two legacy labels, zero modern brand detection.

Understanding the appName Property

appName is a read-only string on Navigator. Historically it meant “application name.” In practice it is a fixed compatibility value.

• Value is always "Netscape" in conforming browsers.
• Kept for old scripts that expected that string.
• Useless for telling Chrome apart from Firefox or Safari.
• Sibling of appCodeName in the legacy Navigator string family.

📝 Syntax

General form of the property:

navigator.appName

Value

• The string "Netscape".

Common patterns

console.log(navigator.appName); // "Netscape"

// Classic legacy pair:
console.log(navigator.appCodeName); // "Mozilla"
console.log(navigator.appName);     // "Netscape"

// Prefer feature detection instead of sniffing:
if ("geolocation" in navigator) {
  // safe to use navigator.geolocation
}

Examples Gallery

Examples follow MDN Navigator.appName behavior. Use View Output or Try It Yourself for each case.

console.log(navigator.appName);
// Netscape

Netscape

const name = navigator.appName;
const isNetscapeLabel = name === "Netscape";

console.log(name);
console.log("isNetscapeLabel: " + isNetscapeLabel);
// Netscape
// isNetscapeLabel: true

Netscape
isNetscapeLabel: true

const lines = [
  "appCodeName: " + navigator.appCodeName,
  "appName: " + navigator.appName,
  "useful for brand detection? no"
];
console.log(lines.join("\n"));
// appCodeName: Mozilla
// appName: Netscape
// useful for brand detection? no

appCodeName: Mozilla
appName: Netscape
useful for brand detection? no

const name = navigator.appName;
console.log(typeof name);
console.log(name.length);
console.log(name.toUpperCase());
// string
// 8
// NETSCAPE

string
8
NETSCAPE

const lines = [];
lines.push("appName: " + navigator.appName + " (ignore for sniffing)");
lines.push(
  "geolocation API: " +
    ("geolocation" in navigator ? "available" : "missing")
);
lines.push(
  "serviceWorker: " +
    ("serviceWorker" in navigator ? "available" : "missing")
);
console.log(lines.join("\n"));

appName: Netscape (ignore for sniffing)
geolocation API: available
serviceWorker: available
(exact API lines depend on your browser)

🚀 Common Use Cases

• Learning Navigator — another fixed read-only string on navigator.
• Reading legacy code — understand checks for "Netscape".
• Teaching anti-patterns — show why sniffing with appName fails.
• Pairing with appCodeName — recognize the classic Mozilla / Netscape duo.
• Not for production branching — do not gate features on this value.

📝 Notes

• Always "Netscape" — not a real browser name.
• Kept only for compatibility with old content.
• Do not use for browser or engine detection.
• Baseline Widely available across modern browsers.
• Related: appVersion, appCodeName, activeVRDisplays, Window.

💡 Best Practices