Validate multiple `.properties` files against one `application.properties` reference file.

Check whether `application-dev.properties`, `application-qa.properties`, and `application-prod.properties` match the keys in `application.properties`.

or Drag multiple properties files here.

application.properties

0 properties are documented in the reference file. 0 of them already include default values.

1Files
0Missing properties
0Extra properties
0Duplicate groups
0Malformed lines
0Warnings

Paste or upload a template and at least one properties file to start.

Add more widgets with the plus button if you want to compare development, QA, and production property files against the same reference template.

FAQ

How this properties file validator works

Does this tool upload any .properties files?

No. Parsing, validation, and comparison all happen locally in the browser.

Can I compare multiple .properties files against one reference file?

Yes. Upload or drag in a full set like application.properties, application-dev.properties, application-qa.properties, and application-prod.properties, and the validator will compare every runtime file against the reference file.

What counts as a missing property?

Every key documented in the reference file is treated as part of the expected contract, even when that reference file includes a default value.

Are duplicate and malformed lines validated in the template too?

Yes. Duplicate keys and malformed lines stay visible in the template and in every compared .properties file.

Which .properties syntax is supported?

The validator covers common Java properties syntax: key=value, key:value, whitespace separators, comment lines starting with # or !, and continuation lines with a trailing backslash.

What does Quick Fix change?

Quick Fix removes malformed property lines, collapses duplicate keys so the last valid value wins, and normalizes line endings and extra spacing. It does not add missing properties or move undocumented properties into the reference file.