Cross-browser compatibility refers to the ability of a website or web application to function correctly across various web browsers. Given the diversity of browsers available today, including Chrome, Firefox, Safari, and Edge, ensuring consistent performance is crucial for enhancing user experience. This compatibility is influenced by various factors such as browser rendering engines, CSS support, and JavaScript execution. To guarantee that users have a seamless experience, developers must adhere to several key principles, such as following web standards, using responsive design techniques, and conducting thorough testing across different environments.

One of the foundational principles of cross-browser compatibility is the use of widely accepted web standards. By structuring your code in compliance with HTML, CSS, and JavaScript specifications set by organizations like the W3C, you can significantly minimize compatibility issues. Furthermore, employing tools like feature detection and graceful degradation assists in creating a more flexible design that adjusts to various browser capabilities. Finally, regularly testing your website using browser testing tools ensures that you catch and fix any discrepancies, enabling a smoother and more uniform browsing experience for all users.

In today's digital landscape, ensuring browser compatibility is crucial for delivering a seamless user experience. Various tools can help developers and designers test their websites across multiple browsers and devices. Some of the top tools for this purpose include:

1. BrowserStack - A popular cloud-based testing tool that allows you to test your website on real devices and browsers.
2. CrossBrowserTesting - This tool offers live testing, automated testing, and screenshot comparisons across hundreds of browsers.

Utilizing these tools not only saves time but also helps in identifying compatibility issues early in the development process. Moreover, tools like LambdaTest and Microsoft Edge DevTools provide robust features for debugging and optimizing user experience. As a developer, investing in reliable browser compatibility testing tools can significantly enhance your workflow and ensure that your website looks and functions perfectly for all users.

When developing a website, common browser compatibility issues can significantly impact user experience and accessibility. Different web browsers interpret code in unique ways, leading to discrepancies in layout, formatting, and functionality. For instance, JavaScript that runs smoothly in Chrome may encounter errors in Firefox or Safari. It's crucial to regularly test your website across various browsers and their versions to identify and address these issues early on. Implementing a robust testing strategy can involve using tools like BrowserStack or CrossBrowserTesting, along with browser developer tools to simulate different environments.

To resolve browser compatibility issues, developers should adopt a number of best practices:

1. Use standard coding practices: Following HTML and CSS standards minimizes discrepancies between browsers.
2. Progressive enhancement: Build your site from a basic level of functionality up to advanced features, ensuring core content is accessible even in older browsers.
3. Feature detection: Utilize libraries like Modernizr to check if a browser supports a feature before attempting to use it.
4. Regular updates: Keeping both your development environment and testing tools up to date can help mitigate known compatibility issues.