netlify.toml

[build]
    command = "npm run build"
    publish = ".next"
    functions = "functions"

[[plugins]]
# https://github.com/philhawksworth/netlify-plugin-minify-html#readme
package = "netlify-plugin-minify-html"

    # Specify which deploy contexts we'll minify HTML in.
    # Supports any Deploy Contexts available in Netlify.
    # https://docs.netlify.com/site-deploys/overview/#deploy-contexts
    [plugins.inputs]
    contexts = [
        'production',
        'branch-deploy',
        'deploy-preview'
    ]

    # Optionally, override the default options for the minification
    # https://github.com/kangax/html-minifier#options-quick-reference
    [plugins.inputs.minifierOptions]
    removeComments = true
    collapseInlineTagWhitespace = true
    collapseWhitespace = true
    minifyCSS = true
    minifyJS = true
    sortAttributes = true
    sortClassName = true