Properties to JSON Converter
Convert Java .properties to JSON and back.
Paste a .properties file to convert.
How to use
- 1 Paste a .properties file, or a flat JSON object.
- 2 Choose the direction: .properties → JSON or JSON → .properties.
- 3 Comments and escape sequences are handled automatically.
- 4 Copy the output or download it as .json / .properties.
About Properties to JSON Converter
The Properties to JSON converter translates Java-style .properties files into a clean JSON object and back again.
The .properties format underpins Spring, Java i18n bundles, Gradle and countless legacy services, but its flat key=value structure is awkward to read, diff or feed into modern JavaScript tooling.
This converter parses it faithfully: keys and values can be separated by = or :, lines beginning with # or ! are treated as comments, and standard escape sequences such as \n, \t, \: and \uXXXX unicode escapes are decoded into their real characters.
Line continuations with a trailing backslash are joined automatically.
Going the other way, a flat JSON object is serialised into valid .properties output, with separators, leading spaces and reserved characters escaped so the file round-trips cleanly.
Because .properties is inherently flat, nested JSON objects are rejected with a clear message rather than being silently flattened in a way that might surprise you.
Everything runs client-side in your browser.
Configuration files frequently hold connection strings, feature flags and secrets, and none of that is ever uploaded.
Paste a file, pick a direction, and copy or download the result.
FAQ
Which separators and comments are supported?
Keys and values may be separated by = or :. Lines starting with # or ! are treated as comments and ignored, matching the java.util.Properties format.
What happens to nested JSON?
The .properties format is flat, so a JSON object whose values are themselves objects or arrays is rejected with a clear error rather than being silently flattened.
Are escape sequences decoded?
Yes. \n, \t, \r, \\, escaped separators and \uXXXX unicode escapes are decoded when reading, and re-escaped when writing .properties output.