Introducing microformats-parser: a new parser for JavaScript

I wrote a microformats parser. Here's why, and how you can also use it.

This site hasn't been going for too long (at the time of writing, at least) - but I've always been inspired to include microformats as part of it. This was triggered by Jamie Tanna's post on marking up pronoun information in HTML. I've included marked-up data in my bio and feed, but I would like to also be able to verify this data is correct and as I expect while I'm making changes.

Unfortunately, I've not found an easy way of checking the parsed result without manually inputting it to an online parser, such as one of the many available at The existing JavaScript microformats parsers are no longer maintained and do not follow the current specification. So naturally, I decided to write my own...

The journey

Initially, I aimed to for the parser to only cover microformats v2 (the latest specification). There was already a fairly comprehensive test suite available, that became my basis of a test-driven development approach. I looked to keep the package lightweight, with only one dependency, parse5, which took the heavy-lifting of transforming a HTML string into a nested tree structure. After this, it became a case of walking through the tree structure, and parsing the microformats as you go.

Although only meant to be a v2 parser, the implementation went quicker than I expected, which meant I decided to extend it to also cover back-compatibility with legacy (v1) and mixed(v1/v2) microformats. At this point I released microformats-parser at v1.0.0 with an in-browser demo page (temporarily unavailable). It was also great that after sharing my parser on #microformats there was a quick community contribution to add experimental lang parsing.

Using microformats-parser

microformats-parser can be installed using npm or yarn and is supported for all active Node.js LTS releases and for the browser via webpack. The demo (temporarily unavailable) runs exclusively in-browser, and the package also comes bundled with TypeScript typings.

Example of use:

import { mf2 } from "microformats-parser";
const html = '<a class="h-card" href="/" rel="me">Aimee</a>';
const parsed = mf2(html, { baseUrl: "" });


  "items": [
      "properties": {
        "name": ["Aimee"],
        "url": [""]
      "type": ["h-card"]
  "rel-urls": {
    "": {
      "rels": ["me"],
      "text": "Aimee"
  "rels": {
    "me": [""]

The base URL is used to resolve relative links, and is typically the URL for the document being parsed

How I'm using it

To verify the HTML I'm generating with eleventy has the correct microformats, I am comparing the snapshots of selected pages parsed using mocha. This is mostly to verify I have not accidentally changed, added or removed a property that changes the data that is contained in the post while tinkering with a template.

Source code

The source code for microformats-parser can be found on GitHub.

Get involved

Use JavaScript and microformats? Please help this project out by contributing - whether that be testing the parser out and creating an issue for a bug, or opening a Pull Request to make a change. Contributions are welcome!


microformats-parser is released under the MIT license.