How are nested YAML keys converted to .properties format?

Each level of YAML nesting becomes a dot-separated segment in the property key. For example, a YAML structure with spring → datasource → url becomes `spring.datasource.url= ` — the same key Spring Boot uses when reading `application.yml`. The conversion is semantically identical to what Spring Boot does internally.

How are YAML arrays (lists) converted for Spring Boot?

YAML sequences are converted using Spring Boot's indexed notation: `myapp.servers[0]=localhost`, `myapp.servers[1]=example.com`. This matches exactly how Spring Boot binds lists via `@ConfigurationProperties`, so the output can be dropped directly into `application.properties` without any changes.

Does the tool handle multi-document YAML (--- separator)?

Yes. YAML files may contain multiple documents separated by `---`. This tool parses all documents and merges their properties into a single output, inserting a comment (`# --- Document N ---`) before each group so you can identify which document each property came from.

Does my YAML leave my device?

No. All parsing and conversion runs entirely inside your browser. Your YAML — which may contain database credentials, API keys, and passwords — is never uploaded to any server, never stored, and never logged. The tool works fully offline once the page has loaded.

What is the difference between application.yml and application.properties in Spring Boot?

Both configure the same Spring Boot environment and are semantically equivalent. YAML (`application.yml`) uses indentation to express hierarchy and is easier to read for deeply nested configs. Properties (`application.properties`) uses flat `key=value` pairs and is required by some CI/CD systems, deployment tools, or legacy infrastructure that only accepts `.properties` files.

Does it work on mobile?

Yes. The tool is mobile-first and works on iPhone Safari and Android Chrome. Paste your YAML into the text area, tap Convert, and copy the result to your clipboard.

YAML to Properties Spring Boot

Convert Spring Boot application.yml to application.properties online — nested keys become dot-separated, arrays use [n] indexing, multi-doc YAML supported. 100% client-side, no upload.

100% client-side · no upload. YAML is converted inside your browser. Credentials and secrets never leave your device.

YAML input (application.yml)

Drag and drop a .yml or .yaml file onto the text area to load it.

Download .properties

Paste YAML above and click Convert.

.properties output (application.properties)

How to use

Paste your Spring Boot application.yml into the input, or drag and drop the file onto it.
Click YAML → .properties — nested keys become dot-separated and arrays use [n] indexing.
Click Copy or Download .properties to save as application.properties.

Related format & data tools

Common Spring Boot conversion use cases

よくある質問

How are nested YAML keys converted to .properties format?: Each level of YAML nesting becomes a dot-separated segment in the property key. For example, a YAML structure with spring → datasource → url becomes `spring.datasource.url=<value>` — the same key Spring Boot uses when reading `application.yml`. The conversion is semantically identical to what Spring Boot does internally.
How are YAML arrays (lists) converted for Spring Boot?: YAML sequences are converted using Spring Boot's indexed notation: `myapp.servers[0]=localhost`, `myapp.servers[1]=example.com`. This matches exactly how Spring Boot binds lists via `@ConfigurationProperties`, so the output can be dropped directly into `application.properties` without any changes.
Does the tool handle multi-document YAML (--- separator)?: Yes. YAML files may contain multiple documents separated by `---`. This tool parses all documents and merges their properties into a single output, inserting a comment (`# --- Document N ---`) before each group so you can identify which document each property came from.
Does my YAML leave my device?: No. All parsing and conversion runs entirely inside your browser. Your YAML — which may contain database credentials, API keys, and passwords — is never uploaded to any server, never stored, and never logged. The tool works fully offline once the page has loaded.
What is the difference between application.yml and application.properties in Spring Boot?: Both configure the same Spring Boot environment and are semantically equivalent. YAML (`application.yml`) uses indentation to express hierarchy and is easier to read for deeply nested configs. Properties (`application.properties`) uses flat `key=value` pairs and is required by some CI/CD systems, deployment tools, or legacy infrastructure that only accepts `.properties` files.
Does it work on mobile?: Yes. The tool is mobile-first and works on iPhone Safari and Android Chrome. Paste your YAML into the text area, tap Convert, and copy the result to your clipboard.

Last updated: 2026-05-20 By jarvisbox

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