JavaScript Navigator appCodeName Property: App Code Name
The navigator.appCodeName property in JavaScript is a read-only string that returns the internal “code name” of the browser. Historically, this property was intended to identify the browser, but due to widespread compatibility measures and the standardization of web technologies, its value is now almost universally "Mozilla" regardless of the actual browser being used.
While appCodeName is not a reliable method for browser detection, understanding its existence and historical context can be valuable for legacy code maintenance and gaining a broader perspective on web browser APIs. 🕰️
Purpose of navigator.appCodeName
The primary purpose of navigator.appCodeName was to provide a way to identify the browser being used to access a web page. However, due to its inconsistent and often misleading value, it is no longer recommended for accurate browser detection. Instead, modern techniques such as feature detection and user-agent analysis are preferred.
Syntax
The syntax for accessing the appCodeName property is straightforward:
let appCodeName = navigator.appCodeName;
navigator: The Navigator object, representing the state and identity of the user agent (browser).appCodeName: A read-only property of the Navigator object that returns the browser’s app code name.
navigator.appCodeName Attributes
The navigator.appCodeName property does not have any attributes to configure. It is a simple, read-only string value.
| Attribute | Type | Description |
|---|---|---|
| Read-Only | Boolean | This property is read-only. Its value cannot be changed. |
| Value | String | Typically returns `”Mozilla”`, regardless of the actual browser. |
Examples
Let’s explore a few examples to demonstrate how the appCodeName property is used (and why it might not be useful for modern browser detection).
Basic Usage
This example demonstrates how to retrieve and display the appCodeName property value.
<!DOCTYPE html>
<html>
<head>
<title>Navigator appCodeName Example</title>
</head>
<body>
<h1>Navigator appCodeName Example</h1>
<p id="appCodeNameResult">The appCodeName is: </p>
<script>
const appCodeNameValue = navigator.appCodeName;
document.getElementById("appCodeNameResult").textContent = "The appCodeName is: " + appCodeNameValue;
</script>
</body>
</html>
Output:
The appCodeName is: Mozilla
Checking appCodeName (Not Recommended)
This example attempts to use appCodeName to check if the browser is Mozilla-based, but it’s unreliable as most browsers return "Mozilla".
<!DOCTYPE html>
<html>
<head>
<title>Navigator appCodeName Check</title>
</head>
<body>
<h1>Navigator appCodeName Check</h1>
<p id="appCodeNameCheckResult"></p>
<script>
let appCodeNameCheckValue = navigator.appCodeName;
let message = "Browser is likely Mozilla-based (but may not be accurate).";
if (appCodeNameCheckValue !== "Mozilla") {
message = "Browser is not Mozilla-based.";
}
document.getElementById("appCodeNameCheckResult").textContent = message;
</script>
</body>
</html>
Output:
Browser is likely Mozilla-based (but may not be accurate).
Using appCodeName with Other Properties (Still Unreliable)
Combining appCodeName with other navigator properties doesn’t improve reliability for browser detection.
<!DOCTYPE html>
<html>
<head>
<title>Navigator Combined Check</title>
</head>
<body>
<h1>Navigator Combined Check</h1>
<p id="combinedCheckResult"></p>
<script>
let combinedCheckValue = navigator.appCodeName + " - " + navigator.appName;
document.getElementById("combinedCheckResult").textContent = "Combined values: " + combinedCheckValue;
</script>
</body>
</html>
Output:
Combined values: Mozilla – Netscape
Note: Relying on navigator.appCodeName for browser detection is highly discouraged. Modern browsers often spoof this value, making it unreliable. Use feature detection or user-agent analysis instead. ⚠️
Modern Alternatives to appCodeName
Instead of using navigator.appCodeName, consider these modern alternatives:
- Feature Detection: Check if the browser supports a specific feature using
typeofor by directly testing for the existence of a property or method. - User-Agent Analysis: Examine the
navigator.userAgentstring, but be aware that it can also be spoofed. Use a robust library for parsing user-agent strings. - Browser Detection Libraries: Utilize well-maintained libraries that provide more accurate browser detection capabilities.
Browser Support
The navigator.appCodeName property is supported by all major browsers, but its value is consistently "Mozilla", making it ineffective for browser detection.
| Browser | Support |
| ————— | ——- |
| Chrome | Yes |
| Firefox | Yes |
| Safari | Yes |
| Edge | Yes |
| Opera | Yes |
| Internet Explorer | Yes |
Conclusion
While the navigator.appCodeName property exists and returns a value, it is not a reliable way to identify the browser being used. Its historical purpose has been superseded by more accurate and modern techniques such as feature detection and user-agent analysis. Use appCodeName with caution, primarily for maintaining legacy code, and avoid it for new browser detection implementations. ✅
