About YAML Formatter Online

YAML Formatter Online started from a small, annoying moment: staring at a Kubernetes manifest that refused to apply, knowing the problem was almost certainly a stray space somewhere, and not wanting to open yet another tab that asked for an email address before it would format a text file.

So this site does one thing and tries to do it properly — take YAML, tell you clearly if it's valid, format it if it is, and convert it to JSON and back when you need that instead. No account, no daily limit, no popup asking to "upgrade to pro" halfway through.

Why we built it this way

Two things mattered to us more than they seem to matter to a lot of similar tools:

• Nothing gets uploaded. The formatter runs entirely in JavaScript in your browser tab. There's no server that ever sees what you paste in, which matters a lot when the YAML in question is a real deployment config with real values in it.
• Errors should actually help. "Invalid YAML" tells you nothing. Pointing at the exact line and column, with a plain description of what went wrong, is the difference between a 5-second fix and a 20-minute one.

Alongside the tool, we've been writing a set of short, plain-English articles about YAML — what it is, where it shows up, and the specific mistakes that come up again and again in Docker, Kubernetes, Ansible and CI configs. You can find all of them on the blog.

Get in touch

If something breaks, formats incorrectly, or you just want to suggest a feature, we'd genuinely like to hear about it — see the contact page for how to reach us.