How do you support legacy browsers and devices?

1 Know your audience

Before you start coding, you need to know who your target users are and what browsers and devices they use. You can use analytics tools, surveys, or user feedback to gather this information. Knowing your audience will help you prioritize the features and functionalities that are most important and relevant for them. It will also help you decide what level of support you want to provide for legacy browsers and devices. For example, you might want to offer a graceful degradation or a progressive enhancement approach, depending on your goals and resources.

2 Use feature detection

One of the best practices for supporting legacy browsers and devices is to use feature detection. Feature detection is a technique that checks if a browser or device supports a certain feature before using it. This way, you can provide fallbacks or alternatives for unsupported features, or enhance your website with extra features for supported ones. You can use native JavaScript methods, such as Modernizr, or CSS properties, such as @supports, to perform feature detection. Feature detection is preferable to browser detection, which relies on user agent strings that can be unreliable or spoofed.

3 Use polyfills and transpilers

Another way to support legacy browsers and devices is to use polyfills and transpilers. Polyfills are scripts that emulate or mimic the behavior of newer features that are not supported by older browsers. For example, you can use a polyfill to enable HTML5 elements, such as <canvas> or <video>, in older browsers. Transpilers are tools that convert newer syntax or code into older ones that are more compatible with legacy browsers. For example, you can use a transpiler to convert ES6 or TypeScript code into ES5 code that can run on older browsers. However, be careful not to overuse polyfills and transpilers, as they can add extra weight and complexity to your code.

4 Use responsive design

Responsive design is a technique that adapts your website layout and content to different screen sizes and resolutions. Responsive design is essential for supporting legacy devices, such as mobile phones or tablets, that have different capabilities and constraints than desktop computers. You can use responsive design principles, such as fluid grids, flexible images, media queries, and viewport meta tags, to create a website that looks good and works well on any device. Responsive design also improves your website's usability, accessibility, and SEO.

5 Use cross-browser testing

Cross-browser testing is a process that tests your website on different browsers and devices to ensure that it works as expected and meets your quality standards. Cross-browser testing is important for supporting legacy browsers and devices, as it helps you identify and fix any issues or bugs that might affect your website's appearance or functionality. You can use cross-browser testing tools, such as BrowserStack or LambdaTest, to automate or simplify your testing process. You can also use browser developer tools, such as Chrome DevTools or Firefox Developer Tools, to inspect and debug your code on different browsers.

6 Use best practices and standards

Finally, one of the best ways to support legacy browsers and devices is to follow the best practices and standards of web development. By using clean, semantic, and valid code, you can ensure that your website is more compatible and maintainable across different platforms and environments. By following the web accessibility guidelines, such as WCAG or ARIA, you can ensure that your website is more inclusive and accessible for users with disabilities or impairments. By following the web performance optimization techniques, such as minification, compression, or caching, you can ensure that your website is faster and more efficient for users with slow or limited bandwidth.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?