🧾 YAML checker

Your YAML

Check YAML Load an example…Valid Compose fileTab indentationBad indentationMissing space after colonDuplicate key CopyClear Also run basic Docker Compose shape checks

What this does and doesn't check

• Valid YAML ≠ valid config. A file can be perfectly good YAML and still be rejected by Home Assistant, Compose or Kubernetes because a key is misspelled or a value has the wrong type. This tool checks syntax. The optional Compose mode only checks the basic shape (a services: map, each with an image or build). It is not the full Compose spec.
• Your text is never run. We parse it with a safe parser (js-yaml, core schema). Custom tags such as !!js/function are not supported and are reported as errors. Home Assistant tags like !secret and !include are accepted as plain values.
• Privacy: no upload, no storage, no analytics on what you paste. Still, remove passwords and tokens before pasting anything anywhere.
• Tips: indent with spaces (2 is common), never tabs. Put a space after every key:. Quote values that contain : or # or start with *, &, !, @ or %. Quote yes/no/on/off if you mean text.

Checking a Compose file for risky image updates? Use the Compose update checker.