How do I compare two MD files online?

Paste the first file into the left box and the second file into the right box of the Markdown diff tool. The result shows added and removed lines immediately. The comparison runs in your browser.

Do my Markdown files leave my computer?

No. The diff runs in the browser with JavaScript. The tool sends no file and no text to a server.

Can I compare .md files without Git?

Yes. Git is not necessary. Copy the text of both files and paste them into the two boxes.

Does the tool compare the Markdown source or the rendered output?

The tool compares the Markdown source, line by line. This shows changes to headings, list marks, and link syntax, which a rendered comparison hides.

Markdown diff guide

Compare MD Files

Compare two .md files line by line in the browser. Paste both versions, read the added and removed lines, and copy the result.

Direct answer

To compare MD files, open the Markdown diff tool, paste the old file in the left box and the new file in the right box, then read the result. The tool marks added lines with a green + and removed lines with a red -. It runs in your browser. No file upload and no login are necessary.

Open Markdown diff tool

When to use this

You have two versions of a README.md and you want the exact changed lines.
You edited a Markdown document outside Git and you have no commit history to diff.
You want to check a Markdown file that an AI tool rewrote, before you keep the new text.

Steps

Open the file that you want to use as the base version in a text editor.
Select all of the text and copy it.
Paste the text into the left box of the Markdown diff tool.
Copy the full text of the second .md file.
Paste that text into the right box.
Read the result: green lines with + are added, red lines with - are removed.

Example

What you paste

LEFT BOX (old README.md)

# Project

A small tool.

## Install

npm install project

## License

MIT


RIGHT BOX (new README.md)

# Project

A small tool that converts Markdown.

## Install

npm install project

## Usage

npx project file.md

## License

MIT

Diff result

  # Project

- A small tool.
+ A small tool that converts Markdown.

  ## Install

  npm install project

+ ## Usage
+
+ npx project file.md

  ## License

  MIT

Common mistakes

Paste the plain Markdown source, not the rendered preview. Rendered text loses the # and * marks and gives a false diff.
Keep the older version in the left box. If you reverse the boxes, the added and removed colors also reverse.
A line that changes by one word shows as one removed line and one added line. The tool compares whole lines, not single words.

FAQ

How do I compare two MD files online?: Paste the first file into the left box and the second file into the right box of the Markdown diff tool. The result shows added and removed lines immediately. The comparison runs in your browser.
Do my Markdown files leave my computer?: No. The diff runs in the browser with JavaScript. The tool sends no file and no text to a server.
Can I compare .md files without Git?: Yes. Git is not necessary. Copy the text of both files and paste them into the two boxes.
Does the tool compare the Markdown source or the rendered output?: The tool compares the Markdown source, line by line. This shows changes to headings, list marks, and link syntax, which a rendered comparison hides.