YAML Formatter
Tidy up messy YAML code and make it readable again. Paste code, format it instantly, and copy the result for your project. Great for quick QA.
YAML Formatter
SIMILAR TOOLS
What this does
So your YAML has gone ragged, the indentation is inconsistent after some copy and paste, and in YAML that is not just ugly, it can change what the file means. This tidies it. Paste your YAML, click Format, and it comes back with clean, consistent indentation.
How to use it
- Paste your YAML into the box.
- Click Format.
- Copy the formatted YAML.
How it works
This uses Prettier with its YAML parser. It reads the keys, values, and lists in your file and rewrites them with even, predictable indentation throughout. The formatting runs in your browser, so your config never leaves your computer.
Why indentation is the whole game in YAML
Here is what makes YAML different from most formats. In YAML, indentation is not decoration, it is meaning. The number of spaces in front of a line decides what belongs to what, so a key nudged in or out by a couple of spaces can quietly change the structure, or break the file entirely. That is why consistent indentation matters so much here, and why a formatter is more than a cosmetic nicety.
Because Prettier parses your YAML rather than just shifting whitespace around, it normalises the whole document to one consistent style, which makes mistakes easier to spot. And if the YAML is genuinely broken, it will stop and tell you, rather than hand back something that looks fine but is not.
Questions people ask
Why does indentation matter so much in YAML?
Because YAML uses indentation to define structure. How far a line is indented decides which key it belongs to, so inconsistent spacing can change the meaning or break the file.
Does formatting change my values?
No. It standardises the indentation and spacing. Your keys, values, and lists keep their content.
Why did it refuse to format?
Prettier parses the YAML, so if the file is invalid it will stop and report the problem instead of guessing.
Is my config uploaded?
No. It runs in your browser, so the YAML you paste stays on your machine.
References
- YAML. YAML Ain't Markup Language (YAML) version 1.2. https://yaml.org/spec/1.2.2/
- Prettier. An opinionated code formatter. https://prettier.io/
Sugam Baskota is a senior software engineer and Computer Science graduate from UT Arlington, with interests in user scripts, browser extensions, developer tooling, and productivity systems. He spends time building practical utilities and extensions in the kinds of workflows Eon is designed to simplify. At Eon Tools, he reviews useful, password, and developer tools.