- Image Compression Tools: TinyPNG, JPEGmini, and ImageOptim are excellent for reducing the size of your images without sacrificing quality. - Code Minification Tools: Use tools like HTMLMinifier, CSSNano, and UglifyJS to minify your HTML, CSS, and JavaScript code. - Email Testing Tools: Platforms like Litmus or Email on Acid can help you test your emails across different clients, ensuring they load quickly and render correctly.