Markdown header sorter

Paste your markdown. Pick a level. Get sections sorted A–Z.

Use this markdown header sorter online to sort markdown headers alphabetically—no install, works in the browser. Markdown sorting by level (# to ######); supports full markdown syntax. Free & open source. See a before and after example and Q&A below.

Examples:
Sort by header level
Markdown format requirements (syntax for headers)

Each markdown header must have a blank line above and below it to be detected. Use standard markdown syntax (e.g. #, ##).

Correct:

# Topic

## My topic

## My other topic

Incorrect:

# Topic
## My topic
## My other topic

(Click “Correct” for a surprise.)

Before and after

Example: unsorted markdown headers become alphabetically ordered. Content under each header stays with its header.

Before

# Zebra

Section about Zebra.

# Apple

Section about Apple.

# Mango

Section about Mango.

After (sorted)

# Apple

Section about Apple.

# Mango

Section about Mango.

# Zebra

Section about Zebra.

Try it with your markdown

Questions and answers

What is a markdown header sorter?

A markdown header sorter is a tool that sorts markdown sections alphabetically by their headings. This one works online in your browser: you paste markdown, choose a header level (# to ######) or sort all levels, and get reordered output. No install needed.

How do I sort markdown headers alphabetically?

Paste your markdown into the input box, ensure each header has a blank line above and below it, then choose "All headers" to sort every level or pick a single level (#, ##, etc.). The result updates live; use "Copy result" to use the sorted markdown elsewhere.

Do I need to install anything?

No. This markdown header sorter runs entirely in the browser. For use in Node.js you can use the open-source script from the GitHub repo.

Why do headers need blank lines above and below?

The tool detects a line as a markdown header only when it has a newline above and below it. That follows common markdown style and avoids misdetecting # in the middle of a sentence. See the format requirements on this page for correct vs incorrect examples.

Can I sort only one header level (e.g. ##)?

Yes. Use the level pills to choose "All headers" (recursive sort) or a single level: #, ##, ###, ####, #####, or ######. Sorting only ## reorders level-2 sections alphabetically and leaves # and ### etc. unchanged.

Is the markdown header sorter free?

Yes. The tool is free to use and open source. No account or sign-up required.