Properties to JSON Converter

Convert Java .properties files to JSON online. Reconstructs nested objects and arrays from dot-notation keys — all in your browser.

Input Properties
Drop .properties file here
JSON Output

Features

☕ Faithful .properties Parsing

  • Dot-notation keys rebuilt into nested objects
  • Numeric segments reconstructed as arrays
  • # and ! comment styles supported
  • Unicode escapes (\uXXXX) decoded

⚡ Privacy-First

  • All parsing happens in your browser
  • No data ever sent to a server
  • Pairs with our JSON to Properties converter
  • Download or copy the resulting JSON instantly

🌱 Spring Boot Migration

  • Inspect an application.properties as structured JSON
  • Convert to application.yml via our other tools
  • Compare config across environments as JSON
  • Optional automatic number/boolean detection

Properties to JSON Guide

Java .properties files are flat by design — a plain list of key=value pairs, with dot-notation (database.host=localhost) as the community convention for expressing structure. Reading a large application.properties file line by line to understand its actual shape is tedious, especially once a project has accumulated dozens of dotted keys from different modules and Spring Boot auto-configuration classes. This tool splits each dotted key back apart and rebuilds the nested JSON object it represents, so you can see the real structure at a glance — the same reverse operation our JSON to Properties tool performs in the other direction.

Keys with consecutive numeric segments (features.0, features.1) are automatically detected and reassembled into a JSON array rather than an object with string-numeric keys — the same convention Spring's @ConfigurationProperties binder uses for list-typed configuration fields.

Frequently Asked Questions

What comment styles are supported?

Both # and ! are valid comment markers in the .properties format (a historical quirk from Java's original spec), and this converter strips full-line comments starting with either character.

Are Unicode escape sequences decoded?

Yes — .properties files are traditionally ASCII-only, so non-ASCII characters are written as \uXXXX escapes (e.g. café for "café"). This converter decodes those back to their actual Unicode characters in the resulting JSON.

What happens to numbers and booleans?

With "Infer types" enabled, values that look like integers, decimals, or true/false convert to their JSON equivalents. Since every .properties value is technically just a string, disable this option if you need exact string preservation for values like version numbers.

Does it support the key:value and key value separator styles?

Yes — the .properties spec allows =, :, or plain whitespace to separate a key from its value, and this parser recognizes all three, checking for the first unescaped occurrence of any of them on each line.

Moving Java properties to JSON or YAML

Many Java teams move configuration from .properties files to YAML or JSON as it grows, because nested structure is easier to read than long dotted keys. Converting is the first step; a few checks keep the migration safe.

Tips and common pitfalls

  • Spring Boot reads application.properties and application.yml equally, so you can convert and switch without code changes. Do not keep both with conflicting values.
  • Placeholders such as ${DB_HOST} are copied as text and resolved at runtime by Spring, not during conversion.
  • Profile-specific files, like application-prod.properties, should be converted separately and keep their profile suffix.
  • Keep secrets out of both formats; use environment variables or a secrets manager instead.

More questions

Which encoding do properties files use?

Historically ISO-8859-1, with non-Latin characters written as \uXXXX escapes. Since Java 9, properties-based resource bundles are read as UTF-8. If non-ASCII text looks wrong after conversion, check which encoding your file was saved in.

How do I turn the JSON into YAML?

Paste the result into our JSON to YAML converter. The nested structure carries over directly.