DevToolKit

Properties to YAML Converter — Convert .properties to YAML Online [2026]

Paste Java .properties → get clean YAML output instantly. Handles nested keys (server.port → server:\n port:), comments, and special characters. Also supports YAML to Properties reverse conversion.

Mode: Properties → YAML

What is Properties to YAML?

Properties to YAML Converter is a free online tool that transforms Java .properties files into YAML format and vice versa. In the Java and Spring Boot ecosystem, configuration can be written in either .properties or .yaml format. Properties files use dot-separated flat keys (server.port=8080), while YAML uses indentation-based nesting. This tool makes migrating between the two formats effortless.

How to Use Properties to YAML

Paste your Java .properties file content into the input area on the left. The tool automatically parses each key-value pair, splits dotted keys into nested YAML structure, and displays the YAML output on the right. For example, server.port=8080 becomes server:\n port: 8080. Toggle the direction switch to convert YAML back to .properties format. Comments starting with # are preserved in the output. Copy the result with one click.

How Properties to YAML Works

For Properties to YAML: The tool reads each line, skipping comments and blank lines. It splits each line on the first = or : delimiter to get the key and value. Dotted keys are split by periods and used to build a nested object tree. The tree is then serialized to YAML with proper indentation. For YAML to Properties: The tool parses the YAML structure into a nested object, then flattens it by joining keys with dots to produce key=value lines.

Common Use Cases

  • Migrating Spring Boot application.properties to application.yml
  • Converting legacy Java properties files to modern YAML format
  • Generating properties files from existing YAML configurations
  • Comparing configuration in both formats side by side
  • Preparing configuration files for different deployment environments
  • Converting Gradle or Maven properties to YAML for documentation

Frequently Asked Questions

What is a .properties file?

A .properties file is a simple text format used in Java applications for configuration. Each line contains a key-value pair separated by = or :. Keys often use dot notation to represent hierarchy, such as server.port=8080 or database.url=jdbc:mysql://localhost/mydb.

Why convert properties to YAML?

YAML is more readable for complex, deeply nested configurations because it uses indentation instead of repeating dot-separated prefixes. Spring Boot supports both formats, and many developers prefer YAML for its clarity and ability to handle lists and multi-line strings.

Does this tool handle nested keys?

Yes. Dotted keys like spring.datasource.url are automatically split and converted to nested YAML structure with proper indentation levels.

Can it convert YAML back to properties?

Yes. Use the direction toggle to switch from Properties → YAML to YAML → Properties. The reverse conversion flattens the YAML hierarchy back into dot-separated property keys.

Are comments preserved?

Comments starting with # in properties files are included as YAML comments in the output. When converting from YAML to properties, YAML comments are preserved as # comments.

Is my configuration data secure?

Yes. All conversion happens in your browser using JavaScript. No data is transmitted to any server.

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