Java – Detecting Firefox Browser

The post shows you the way how to detect if a browser is Firefox or not using Java.


1. Implementation

The code looks simple as this.
package com.bytenota;

import javax.servlet.http.HttpServletRequest;

public class Browser {
    public static boolean detectFirefox(HttpServletRequest request) {
        String userAgent = request.getHeader("User-Agent").toLowerCase();
        return userAgent.contains("firefox");

In the above code, we simply look at User-Agent data (request.getHeader("User-Agent")). if it contains firefox string, the browser is Firefox. Otherwise, the browser is something else, it can be Chrome, Edge, IE, Safari, or whatever.


2. Usage and Example

Let’s create a jsp file in your web application with the following content.

<%@page import="com.bytenota.Browser"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Java - Detecting Firefox Browser</title>
            if (Browser.detectFirefox(request)) {
                out.write("The browser is Firefox");
            } else {
                out.write("The browser is not Firefox");

Assuming that you have opened this jsp webpage in the Firefox browser. And the output you will get is:

The browser is Firefox