YAML Editor

An online YAML editor with live checking

This YAML editor is meant for the small edits you make outside your usual environment: adjusting a CI workflow on a borrowed machine, fixing a Compose file from a support ticket, or preparing a config snippet for documentation. You type in a syntax-highlighted editor, and the page parses the file after every change, so indentation mistakes show up immediately with their line and column rather than when a pipeline fails.

An editing loop that catches mistakes early

1. Edit in the input panel. Highlighting separates keys, strings, numbers and comments.
2. Check the tree. With View Tree selected, the Tree tab shows the parsed structure. If a key you meant to nest under env appears at the top level instead, the indentation is wrong.
3. Read errors in the status bar. Invalid YAML produces messages such as bad indentation of a mapping entry (line 3, column 2).
4. Format when you are done, to normalize indentation to 2 or 4 spaces with comments kept.

Example: a nesting mistake the tree reveals

services:
  web:
    image: nginx:1.27
  ports:
    - "8080:80"

This is valid YAML, so there is no error message, but the tree shows ports as a sibling of web rather than a child of it. Indenting ports two more spaces moves it under web, and the tree updates as you type. Mistakes like this are exactly the kind that syntax checking alone cannot catch.

The three actions

• View Tree – parses the YAML and shows a collapsible tree plus a nested table in Preview and the data as JSON in Code.
• Format – tidies the YAML itself, keeping comments. Pick the Indent (2 or 4 spaces) first.
• Validate – confirms the file parses and reports the number of documents for multi-document files.

Keeping your work

There are three ways to keep what you edited: Copy, Download (saves the output panel), and Save & Share, which stores the input and options on our server and gives you a link you can reopen or send to a colleague. Remember that anyone with the link can see the content, so remove secrets such as passwords and tokens first.

Tips for editing YAML by hand

• Never indent with tabs; YAML rejects them.
• Quote values that contain : or start with characters like @, *, & or !.
• Quote version numbers and codes with leading zeros, e.g. "1.10" and "01234", or they become numbers.

For purely read-only exploration, the YAML viewer is simpler, and the JSON editor gives you the same workflow for JSON. To compare your edited file with the original, paste both into the diff checker.

Privacy

Editing, parsing and formatting happen in your browser. Content is sent to our server only when you use Load URL or choose to Save & Share.