Fix Classes Not Working in Tailwind: CSS Build Solution (2026)
How to Fix “Classes Not Working” in Tailwind (2026 Guide) The Short Answer To fix the “Classes Not Working” issue in Tailwind, ensure that your configuration file is properly set up and that the purge option is correctly configured to include the necessary CSS classes. This can typically be achieved by updating the tailwind.config.js file to include the correct paths and settings. Why This Error Happens Reason 1: The most common cause of this issue is an incorrect or incomplete configuration in the tailwind.config.js file, particularly in the purge section, which determines what CSS classes are included in the final build. For example, if the purge option is set to an empty array, no CSS classes will be included, resulting in the “Classes Not Working” error. Reason 2: An edge case cause of this issue is when using a custom build process or a third-party plugin that modifies the Tailwind configuration, potentially overriding the purge settings and causing the error. This can happen when using tools like Webpack or Rollup with custom configurations. Impact: The impact of this error is a failed CSS build, resulting in a non-functional or partially functional application, as the necessary CSS classes are not being generated. Step-by-Step Solutions Method 1: The Quick Fix Go to tailwind.config.js > module.exports and locate the purge option. Toggle the purge option to include the necessary paths, for example: purge: ['./src/**/*.html', './src/**/*.js']. Refresh the page or re-run the build process to apply the changes. Method 2: The Command Line/Advanced Fix To fix the issue using the command line, you can update the tailwind.config.js file to include the correct purge settings and then run the following command: ...