RunKit + npm: marked

const marked = require("marked") const Slugger = require("github-slugger"); const slugger = new Slugger(); // extend renderer const renderer = new marked.Renderer(); renderer.heading = function(text, level, raw) { const slug = slugger.slug(raw); return `<h${level} id="${slug}">${text}</h${level}>\n`; }; const options = { renderer }; const md = `# heading ## heading # heading again ## heading again`; const html = marked(md, options);