.properties Converter Free Online
Parse Java .properties files and convert them to JSON — or convert JSON back to .properties format. Works with Spring Boot application.properties, Java resource bundles, and more. Runs in your browser.
.properties Input
JSON Output
JSON Input
.properties Output
Pro — .properties ↔ YAML, Spring Boot profiles merge, API access
API access · Priority queue · Team workspace
How It Works
Paste .properties
Paste your Java .properties file (application.properties, messages.properties, etc.) or click Sample to load a Spring Boot example with server, datasource, and JPA settings.
Choose Output Mode
Toggle "Nested" to expand dotted keys (spring.datasource.url) into a deeply-nested JSON object, or leave it off for a flat key→value JSON map. Both modes update in real time.
Copy JSON
Click Copy to get the JSON output. Switch to the JSON → .properties tab to do the reverse: paste flat JSON and get a ready-to-use .properties file.
.properties Converter Features
Flat and nested JSON, bi-directional conversion, Spring Boot compatible
Full Format Support
Parses key=value and key: value pairs, # and ! comments, backslash line continuations, and Unicode escape sequences (\uXXXX) as defined in the Java Properties spec.
Flat & Nested JSON
Toggle Nested mode to expand dotted keys like spring.datasource.url into hierarchical JSON objects — ideal for visualising Spring Boot or Micronaut configuration structure.
Bi-Directional
Convert .properties → JSON for code and APIs, or JSON → .properties to generate config files for Java projects without having to type each key by hand.
Real-Time Output
Both tabs update instantly as you type — no submit button needed. Makes it fast to experiment with different property values and see the JSON structure change live.
Key Count & Validation
A status badge shows how many key-value pairs were parsed and flags any parsing issues, so you can catch malformed lines before they cause runtime errors in your Java app.
100% Offline
All parsing runs in your browser. No property data — including database passwords, secret keys, or API tokens from Spring Boot configs — is ever sent to a server.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| .properties → JSON | ||
| JSON → .properties | ||
| Nested JSON output | ||
| .properties ↔ YAML | — | |
| Spring Boot profile merge | — | |
| REST API access | — |
Frequently Asked Questions
A .properties file is a plain-text configuration format used heavily in Java (Spring Boot, Micronaut, Java EE), Android, and other JVM languages. Each line contains a key=value pair; lines starting with # or ! are comments.
When Nested is checked, keys with dot-notation (e.g. spring.datasource.url) are expanded into nested JSON objects ({"spring":{"datasource":{"url":"…"}}}). This reflects how Spring Boot resolves hierarchical config. Unchecked gives a flat key→value map.
Yes. A backslash at the end of a line means the value continues on the next line (leading whitespace is trimmed). This is part of the Java Properties specification and is fully supported.
The free tool converts JSON ↔ .properties. To convert application.yml, first use the YAML to JSON tool to get JSON, then use the JSON → .properties tab here. Direct YAML → .properties conversion is a Pro feature.
Yes. Unicode escape sequences like \u00e9 (é) are decoded to their actual characters in the JSON output, matching Java's Properties.load() behaviour.
No. All parsing and conversion runs in your browser using JavaScript. No property data is ever transmitted to any server, keeping Spring Boot secrets, database URLs, and API keys private.