The Selenium file upload feature allows developers to upload files using Webdriver's native file upload feature. With Selenium 3, the `setFileDetector` method can be used to let WebDriver know that files are being uploaded from a local computer to a remote server, eliminating the need for changes in test code when switching from local to remote drivers. This feature is available in all official Selenium 3 bindings and requires Selenium 2.8.0 or newer. Examples of file upload tests are provided in Java and Ruby, demonstrating how to use the `sendKeys` command with a local file path and setting up a file detector for remote testing. Additionally, Sauce Labs provides a cloud-based platform for automated testing, supporting Selenium, Appium, and JavaScript unit testing frameworks, and offers features such as video recording, debugging tools, and secure tunneling for efficient test suites.