TOML Formatter
Format and validate TOML with consistent structure and optional key sorting.
.properties File Formatter
Format and clean Java .properties files, with options to sort keys, remove duplicates, and convert to YAML or JSON.
Input data is processed in your browser
Data is never sent to a server
Tool
What is the .properties File Formatter?
This tool helps you format, clean, and convert Java .properties files — the configuration format used in Java and Spring Boot projects.
It supports sorting keys alphabetically, removing duplicate entries, unifying separators, aligning values, and preserving comments. It can also convert dotted-key properties into a nested YAML structure or a flat JSON object, which is useful when migrating between frameworks or cleaning up legacy configuration files.
How to Use
- Paste your .properties file content into the input field. Click "Sample" to see an example.
- In the "Format" tab, choose your output separator, enable value alignment, and toggle comment preservation.
- In the "Convert to YAML" tab, dotted keys like `server.port=8080` are converted into a nested YAML structure.
- In the "Convert to JSON" tab, all keys are output as a flat JSON object.
- Enable "Remove duplicate keys" to keep only the last occurrence of any repeated key.
- Click "Download" to save the result as a `.properties`, `.yaml`, or `.json` file.
FAQ
Which separators are supported?
Both `=` and `:` are recognized as separators in the input. For the output, you can choose between `=`, ` = ` (with spaces), `:`, and `: ` in the Format tab options.
Are Unicode escapes (\uXXXX) handled?
Yes. Unicode escape sequences like `\uXXXX` in the input are decoded to their actual characters during parsing. The output uses the decoded characters directly.
Is multi-line continuation with backslash supported?
Yes. If a line ends with `\`, it is joined with the next line and treated as a single value.
How are dotted keys handled in YAML conversion?
A key like `server.port=8080` is converted to a nested YAML structure such as `server: port: 8080`. All dots in a key are interpreted as hierarchy separators.
Can this be used directly with Spring Boot's application.properties?
Yes, the tool is compatible with the Spring Boot application.properties format. Spring-specific placeholders like `${...}` are treated as plain strings.