YAML to JSON
Runs 100% in your browserConvert YAML to valid, formatted JSON online — parse nested objects, arrays, flow collections, multi-document YAML, scalars, comments, and local YAML files privately in your browser.
YAML document
JSON formatting
JSON result
Conversion statistics
Recent conversions
Successful conversions appear here as metadata only. YAML and JSON content are not stored.
Private browser conversion
Parsing, diagnostics, formatting, copying, and downloading happen on this device. ToolsSonic does not upload, log, or persist your YAML or generated JSON. Review output before using it in production because YAML features such as anchors, tags, and custom types may not map directly to standard JSON.
Frequently asked questions
A YAML to JSON converter parses a YAML document and serializes its data as standard JSON. Mappings become JSON objects, sequences become arrays, and common YAML scalars such as strings, numbers, booleans, and null values are converted to their JSON equivalents.
Paste YAML into the input panel, load the sample, or open a local .yaml or .yml file. Choose two spaces, four spaces, tab indentation, or compact JSON, then select Convert YAML to JSON. The parser and export actions run locally in your browser.
Yes. The converter handles indentation-based nested mappings, sequence lists, arrays of objects, inline flow objects such as {name: Ada}, and flow arrays such as [red, green]. It reports indentation and structure errors instead of silently flattening nested data.
Yes. ToolsSonic reads a selected YAML file through the browser FileReader API and does not send the content to a conversion server. The input remains in page memory for the current tab, while the optional session history stores only metadata such as document count and output size.
Yes. When a YAML input contains document markers such as `---`, the tool detects the documents. Choose Convert first document to return the first document, or Convert all as JSON array to return every parsed document in a JSON array.
The local parser recognizes quoted and plain strings, integers, decimal numbers, hexadecimal, octal and binary integers, booleans such as true and false, common YAML boolean forms such as yes and no, and null values such as null and ~. Date-like values remain strings because JSON has no native date type.
No. JSON does not have a standard comment syntax, so YAML comments are treated as source annotations and are not included in the JSON output. Keep the original YAML file if comments or documentation notes are important to your workflow.
YAML uses indentation to describe parent-child relationships. A mapping or list item indented under another key becomes nested data, while inconsistent indentation can change the structure or make the document invalid. Use spaces consistently and review the line-and-column diagnostic when conversion fails.
The converter intentionally reports anchors, aliases, and unsupported custom tags rather than guessing at their meaning. These YAML features can create shared references or application-specific types that standard JSON cannot represent directly. Resolve or expand them in a YAML-aware application before conversion when needed.
You can convert the ordinary mappings, sequences, strings, numbers, booleans, and null values found in Kubernetes, Docker Compose, CI, and application configuration YAML. The result is a data representation, not a platform validator; run the generated JSON through the target platform or schema checks before deployment.
YAML to JSON reads YAML syntax and produces strict JSON. JSON to YAML reads strict JSON and produces a more human-oriented YAML representation. The paired ToolsSonic tools are useful for reviewing format changes, but YAML features such as comments, anchors, and tags may not survive a round trip into standard JSON.
Yes. ToolsSonic provides the converter without an account, and parsing, formatting, copying, and downloading run in the browser. The site does not upload, log, or persist the YAML or generated JSON. Clipboard managers, browser extensions, screenshots, and shared devices remain separate privacy considerations.
No. The tool is fully available without creating an account, providing an email address, or paying anything. Open the page, paste or load YAML, and convert immediately. There is no rate limit, no watermark on the output, and no session expiry.
Choose Compact JSON from the Indentation dropdown before running the conversion. Compact output removes all whitespace and newlines between JSON tokens, which reduces byte size for use in API payloads, configuration scripts, or embedded data fields. You can switch back to 2-space or 4-space indentation at any time without re-entering the YAML.
Paste the YAML front matter block directly into the input — without the surrounding --- markers — and run the conversion. The parser will return the front matter fields as a JSON object. Alternatively, include the --- markers and choose Convert first document to isolate the front matter from the rest of the file.
What is YAML to JSON?
What Is a YAML to JSON Converter?
A YAML to JSON converter parses a human-readable YAML document and serializes its data as standard JSON. Mappings become JSON objects, sequences become arrays, and YAML scalars — strings, numbers, booleans, null, and date-like values — map to their JSON equivalents. The conversion is useful whenever a tool, framework, or API expects JSON input but the source data is written in YAML: Kubernetes configuration, Docker Compose files, GitHub Actions workflows, Ansible playbooks, OpenAPI definitions, and application settings all arrive in YAML form.
What Makes ToolsSonic's YAML Parser Different?
ToolsSonic's YAML to JSON Converter is a zero-dependency, pure-JavaScript, indentation-aware parser that runs entirely in your browser — no upload, no server API call, no rate limit. It supports:
Nested mappings and sequences — indented block mappings become nested JSON objects; block sequences with - markers become JSON arrays. Mixed nesting, sequences of mappings, and mappings inside sequences are all resolved correctly.
Flow collections — inline YAML objects such as {host: localhost, port: 8080} and inline arrays such as [read, write] are parsed the same as block style.
Scalar types — quoted strings (both single and double), plain scalars, integers, decimal numbers, hexadecimal, octal and binary notation, all boolean forms (true/false/yes/no/on/off), and null variants (null/~/Null).
Block text — literal block scalars (|) and folded block scalars (>) preserve multi-line strings correctly.
Multi-document YAML — when the input contains --- separators, the parser detects each document. Choose Convert first document for single-document use or Convert all as JSON array to get every document in one JSON array.
Line-and-column diagnostics — when the YAML is invalid, the converter shows the exact line, column, source text, and a pointer character (^) alongside a specific error message and a checklist tip. This is dramatically more useful than a generic "parse error" message.
How to Use the YAML to JSON Converter
1. Paste YAML into the input panel, click Load sample to see a working example, click Paste to read from your clipboard, or use Open YAML file to load a local .yaml or .yml file without uploading it.
2. Choose formatting — 2 spaces, 4 spaces, Tab, or Compact JSON.
3. Choose document mode — first document or all as JSON array.
4. The input and output panels update automatically as you type. Press Convert YAML to JSON to force a manual run.
5. Copy JSON to the clipboard or Download JSON as a .json file.
Common Use Cases
- Kubernetes and Docker Compose — convert deployment YAML to JSON for tooling, scripting, or schema validation.
- GitHub Actions and CI/CD — inspect workflow files as JSON objects for debugging or templating.
- Ansible playbooks — convert task lists and variable files to JSON for integration with Python or JavaScript tooling.
- OpenAPI and JSON Schema — move between YAML and JSON representations of API definitions.
- YAML front matter — extract page metadata written as YAML front matter into a JSON object for a content pipeline.
- Multi-document YAML — convert stream documents separated by --- markers into a single JSON array.
- Local file conversion — open any .yaml or .yml file directly in the browser without choosing an upload service.
Privacy and Data Handling
All parsing, formatting, copying, and downloading happens on this device. ToolsSonic does not receive, store, or log any YAML input or JSON output. The optional recent-conversion list visible at the bottom of the tool stores only non-content metadata — document count, key count, output size, and timestamp — never the actual YAML or JSON text. Your Kubernetes secrets, API tokens, and application configuration stay on your machine.
Supported and Unsupported YAML Features
The converter handles the YAML subset used in the vast majority of configuration files. YAML anchors (&), aliases (*), and custom application tags (!mytag) are reported rather than silently mishandled, because these features can create shared references or application-specific types that standard JSON cannot represent. Non-finite numbers (.inf, .nan) are also reported because JSON has no representation for them. Tabs in indentation are detected and flagged with a clear message. If your YAML uses anchors or aliases, resolve them in your YAML editor first, then convert.
Common use cases
- Converting a Kubernetes deployment YAML to JSON for schema validation or tooling
- Converting a Docker Compose file to JSON for a JavaScript integration test
- Parsing GitHub Actions workflow YAML into JSON for debugging
- Converting Ansible playbook variables to JSON for a Python script
- Extracting YAML front matter from a Markdown file as a JSON object
- Converting multiple YAML documents separated by --- into one JSON array
- Opening a local .yaml or .yml file without uploading it to a server
- Diagnosing indentation, duplicate-key, quoting, and unsupported-tag errors with line-and-column output
Why use ToolsSonic's YAML to JSON?
ToolsSonic's YAML to JSON Converter uses a browser-only indentation-aware parser with no external dependencies. It handles nested mappings and sequences, quoted and plain scalars, flow objects and arrays, block text, YAML document markers, multi-document selection, and clear line-and-column diagnostics. Choose readable JSON with two or four spaces, tab indentation, or compact output, then copy or download the result. Input stays in page memory and the optional recent-conversion list stores only non-content metadata. YAML features such as anchors, aliases, custom tags, and non-finite numbers are reported rather than silently misrepresented in standard JSON. The tool works on Kubernetes, Docker Compose, GitHub Actions, Ansible, OpenAPI, and any other YAML-based configuration format.
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