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YAML / Properties Converter

Designed for Java configuration and resource-key lists. Nested objects flatten to dotted paths, arrays become JSON text, and imported values stay strings to avoid unreliable inference.

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Converted output

Tool guide

What is YAML / Properties Converter?

YAML and Properties Converter supports Java application settings, resource-key lists, and general key/value files. Nested objects flatten into dotted paths, arrays stay JSON text, and control characters are escaped; import rebuilds object structure while rejecting duplicates, conflicting paths, and prototype-pollution keys. Common workflows include the following. Flatten YAML into Java Properties. Convert resource keys into nested YAML. Review dotted-path conflicts and escapes. The page also documents input boundaries, output behavior, and practical cautions so you can review the result before putting it into an application, configuration, test, or production workflow.

When to use it

  • Flatten YAML into Java Properties.
  • Convert resource keys into nested YAML.
  • Review dotted-path conflicts and escapes.

How to use it

  1. Paste a YAML object or Properties text.
  2. Decide whether dots represent nested paths.
  3. Review how arrays will be stored as JSON text.
  4. Convert and resolve conflicting paths.
  5. Check string typing before copying.
  6. Load one of the realistic examples first to verify the selected options and processing direction before replacing it with your own data.

Runnable examples

The “Example 1” and “Example 2” buttons load the matching inputs. They cover different structures, directions, or boundaries and can be run directly in the workspace.

Example 1

app:
  name: JSONLane
  locale: en
build:
  branch: develop
  tools: 50
ports: [80, 443]

Example 2

app.name=JSONLane
app.locale=en
build.branch=develop
build.tools=50
message=Line one\nLine two

Input rules

  • The YAML root must be an object.
  • Properties entries require a separator.
  • Conflicts, duplicates, and dangerous keys are rejected.
  • Text input is counted before processing and is limited to 1,000,000 characters on this page; file modes apply the separate file limit shown in the workspace.
  • Dots expand into nested paths during import.

Output rules

  • Nested objects use dotted paths.
  • Arrays become JSON text.
  • Imported values remain strings.
  • Output reflects only the current input, direction, and options; rerun after changing a mode or value instead of treating an earlier result as current.
  • Arrays export as JSON text and types are not inferred.

Limitations and cautions

  • Dots expand into nested paths during import.
  • Arrays export as JSON text and types are not inferred.
  • Not every historical Java Properties dialect is supported.

How your data is handled

All parsing, format conversion, Base64 work, and intermediate data remain in the current browser tab. JSONLane does not upload the input or retain it after refresh or close.

FAQ

Is YAML or Properties content uploaded?

No. Parsing, conversion, and output generation remain in the current browser tab.

Is every round trip lossless?

No. Comments, layout, type systems, and binary capabilities differ, so the page identifies the areas that require review.

Why can valid input still be rejected?

The destination may not have a safe representation. Dangerous keys, unsafe integers, excessive depth, and ambiguous mappings are rejected instead of silently rewritten.

Do dots always mean nesting?

They do during import, so a literal dotted key cannot be distinguished losslessly.

How are arrays exported?

They are stored as JSON text rather than split ambiguously on commas.

Are Unicode escapes supported?

Import supports common \uXXXX escapes, while export keeps readable Unicode.

Updated: 2026-08-09