Firefox holds 7% of the global browser market share and is the fourth most popular browser worldwide. It remains a significant player with strong brand recognition, and optimizing websites for it is crucial for ensuring a seamless user experience across all platforms.
Debugging and testing for Firefox help establish credibility and provide users a more inclusive, browser-agnostic experience.
This article will guide developers and QAs through performing remote debugging on Firefox, building on previous discussions about Chrome debugging.
Why Perform Remote Debugging?
Below are the reasons why you should perform remote debugging:
- Cross-Device and Browser Compatibility: Remote debugging enables testing on real devices and browsers, ensuring websites work smoothly across various platforms and operating systems without physical access.
- Real-Time Issue Identification: Developers can debug issues instantly on remote devices, simulating real-world conditions like mobile environments and network variability to catch problems early.
- Increased Efficiency: Remote debugging reduces the time spent on manual device configurations and allows developers to focus on solving problems, speeding up the development process.
- Simplified Collaboration: Teams can share live debugging sessions remotely, improving communication and making it easier to resolve issues quickly with real-time input from multiple developers.
- Access to Remote Resources: Debugging remotely removes the need for constant device switching, providing access to various devices, configurations, and settings in a centralized platform.
Remote Debugging Protocol for Firefox
The Mozilla debugging protocol enables a debugger to connect to a browser and inspect various elements such as JavaScript threads, DOM nodes, CSS rules, and other client-side technologies. It provides a unified interface to monitor and modify the execution of web applications.
Key points of the protocol include:
- Debugging and Inspection: This allows the debugger to discover which elements, such as JavaScript threads and DOM nodes, can be debugged or inspected.
- Communication: All communication between the debugger (client) and the browser (server) uses JSON objects, ensuring the protocol is human-readable, easy to implement, and extensible.
- Flexibility: The protocol is designed to be general enough to support various clients (e.g., profilers) and servers (e.g., mail readers, XULrunner applications).
- Implementation: The protocol operates at the JavaScript level, assuming that the JavaScript implementation is functioning properly, not at the lower machine or C++ level.
- Resilience: While bugs may occur in the JavaScript program being executed, they should not corrupt the internal state of the JavaScript implementation itself.
Steps to Perform Remote Debugging on Firefox for Websites
Here are two methods to perform Remote Debugging on Firefox for Websites.
Method 1: Using Firefox DevTools
Below are the steps to perform remote debugging on Firefox for websites using Firefox DevTools.
Step 1: Enable Remote Debugging
- On the remote device, go to about:config in Firefox.
- Set devtools.debugger.remote.enabled to true and choose a port.
Step 2: Enable USB debugging on the device (for mobile) and connect it to your computer.
Step 3: On your local Firefox, go to about:debugging and connect to the device using the IP address and port.
Step 4: Launch the website you want to debug on the remote device.
Step 5: Use local Firefox developer tools (F12) to inspect elements, debug JavaScript, and monitor network activity.
Step 6: End the session by disconnecting the remote device and closing the developer tools.
Method 2: Using BrowserStack Live
BrowserStack’s real device cloud enables developers and QAs to remotely debug websites on real Firefox browsers(multiple versions) instantly without any complex setup.
Developers and QAs get instant access to Firefox (version 3 – version 89) running on the latest and legacy versions of Windows and macOS. Additionally, developers get instant access to Firefox DevTools on their chosen Browser-OS combination. This makes it easy for them to remotely debug websites on Firefox.
Follow the steps below to get started with remote debugging on Firefox:
- Signup for a free trial on BrowserStack Live.
- Log in. Navigate to the Live dashboard.
- Choose the desired OS platform to test on (Windows, macOS). Let’s consider Windows 8 as an example in this case.
- Select the version of Firefox on which the website needs to be debugged.
- A new Live session will be initiated for Firefox (version 89) in a real Windows 10 environment.
- Navigate to the website that needs to be tested (In this case, Google) and start debugging using Firefox DevTools.
Open Firefox DevTools by pressing the shortcut -> F12 on Windows or Cmd + option + I for macOS. One can also right-click and select the Inspect Element feature to initialize DevTools.
That’s how effortlessly one can debug on Firefox (multiple versions of Firefox) directly from their browsers without any complex setup. As developers and testers get remote access to Firefox DevTools operating in real user conditions, debugging JavaScript, HTML, and CSS on specific Firefox versions becomes faster, effortless, and more efficient.
Note: One can also remotely perform Firefox debugging for websites under development or behind a firewall using BrowserStack’s Local Testing feature. Refer to this complete documentation on Local Testing to get started. Comprehensive debugging in the initial stages helps developers avoid critical bugs later.
Useful Resources for Firefox
- How to Inspect Element in Firefox
- How to Perform Remote Firefox Debugging
- How to run Selenium tests using Firefox WebDriver
- Understanding Firefox Headless
- How to downgrade/download to older versions of Firefox
- How to set Proxy in Firefox using Selenium WebDriver?
- How to run Selenium tests using Firefox WebDriver
- How to run Cypress Tests on Firefox Browser
- How to enable Responsive Design Mode in Safari and Firefox?
- How to run Tests in Puppeteer with Firefox
Conclusion
It’s critical to bear in mind that web users across the globe use different versions of Firefox to access the internet. It’s not possible for every user to migrate to the latest versions immediately, every time a new version is released. Consequently, it becomes very important for developers to ensure that their website is optimized for both the latest and earlier versions of Firefox.
Without an easily accessible cloud-based testing infrastructure, remote debugging on Firefox for Windows and macOS would require a real device lab. Needless to say, such device labs demand significant financial investment. Additionally, updating and maintaining device labs is an effort-intensive task. Adopting a real device cloud provides a cost-effective and convenient alternative by cutting out those overheads entirely.
BrowserStack’s extensive cloud infrastructure empowers testers by providing them with the ability to test on Firefox remotely. Teams do not need to worry about investing huge amounts or setting up complex device labs. They just need to sign up for free, choose the desired operating system, the required Firefox version and start testing their website.
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