Properties ↔ YAML Converter - Online Spring Boot Config Tool
Convert Java .properties files to YAML and back. Bidirectional, in-browser, with dot-key nesting, array support, and type inference.
Paste a Spring Boot application.properties or a YAML file and get the other format instantly. Dotted keys are nested into a tree, list-indexed keys become sequences, and primitives are detected automatically. Comments in YAML output are preserved on round-trip; properties syntax (\uXXXX escapes, line continuations, # and ! comments) is fully supported.
How to use
- 1
Pick a direction
Use the swap button to choose .properties → YAML or YAML → .properties.
- 2
Paste your input
Drop a Spring Boot application.properties or any valid YAML into the left panel.
- 3
Tweak options
Toggle dot-key nesting and type inference under Settings if you need flat keys or strict strings.
- 4
Copy or download
Use Copy or Download on the right panel — your data never touches a server.
FAQ
Q.Are dotted keys nested by default?
Yes. app.db.host is converted to app: { db: { host: ... } }. Turn off Nest dotted keys to keep flat keys.
Q.How are arrays detected?
If all child keys of a prefix are consecutive non-negative integers starting at 0 (servers[0], servers[1], …, or servers.0, servers.1, …), the prefix becomes a YAML sequence. Otherwise it stays an object.
Q.Will my data be sent anywhere?
No. All parsing and serialization runs in your browser. There is no server-side processing.
Q.Does YAML → properties preserve comments?
Inline YAML comments are not representable in .properties without ambiguity, so they are dropped. The reverse direction (properties → YAML) preserves # and ! comments as YAML comments.
Q.What happens if a=1 and a.b=2 both appear?
The nested form wins (matches Spring Boot behavior). A warning is shown and the scalar a is discarded.