JSON ↔ Properties Converter - Nest JSON Config Online
Convert JSON to Java .properties and back. Bidirectional, in-browser, with dot-key nesting, array support, and type inference.
Paste any JSON object and get a flat .properties file instantly — or go the other way and reconstruct a nested JSON from dotted keys. Both directions run entirely in your browser with no server involved. Dotted keys are nested into a tree, list-indexed keys (servers[0], servers.0) become JSON arrays, and primitives like true, false, null, and numbers are detected automatically. Choose bracket or dot notation for arrays when converting JSON to .properties.
How to use
- 1
Pick a direction
Use the swap button to choose JSON → .properties or .properties → JSON.
- 2
Paste your input
Drop any valid JSON object or a .properties file into the left panel, or click Load sample to try an example.
- 3
Tweak options
Open Settings to toggle dot-key nesting, type inference, key order, or array notation style.
- 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 handled?
When converting .properties → JSON, consecutive integer-indexed keys (items[0], items[1] or items.0, items.1) become a JSON array. When converting JSON → .properties, choose bracket notation (items[0]) or dot notation (items.0) in Settings.
Q.Will my data be sent anywhere?
No. All parsing and serialization runs in your browser. There is no server-side processing.
Q.What happens if a=1 and a.b=2 both appear?
The nested form wins. A warning is shown and the scalar a is discarded in favor of the nested object.
Q.Is a JSON → .properties → JSON round-trip lossless?
Yes for objects with string, number, boolean, null, and array values. Key order may change if preserve order is disabled. Top-level arrays are not supported — the root must be an object.