YAML Converter Online — Free JSON to YAML & YAML to JSON

Popular Text & Data tools

• jq Playground & Filter BuilderInteractive jq expression tester, filter builder, and JSON transformer powered by WebAssembly.
• Git Conflict ResolverVisually resolve Git merge conflicts by picking current, incoming, or both versions.
• Text Case ConverterConvert text between 20+ case formats: camelCase, snake_case, kebab-case, Title Case, and more.
• Markdown PreviewPreview and render Markdown with GFM, math, Mermaid diagrams, and export options.
• CSV to JSONConvert CSV/TSV to JSON and JSON to CSV with type inference and multiple output formats.

How to YAML Converter Online

1. 1

   Paste your raw JSON or YAML configuration into the input editor, or click Upload to load a .json, .yaml, or .yml file directly from your disk.

2. 2

   DevFlow automatically detects your input syntax: JSON inputs convert to clean YAML, and YAML inputs convert to formatted JSON. You can also manually force a conversion direction using "JSON → YAML" or "YAML → JSON".

3. 3

   Configure YAML formatting options: choose 2-space, 4-space, or 8-space indentation, toggle block vs flow collection styles, and pick plain, single, or double quotes.

4. 4

   Enable "Sort Keys" to recursively order all object keys alphabetically for consistent, clean Git diffs and reproducible configuration deployments.

5. 5

   Click "Convert" or press ⌘↵ (Ctrl+Enter) to transform data instantly, or click "Validate" (⌘⇧V) / "Format" to audit syntax with line and column error markers.

6. 6

   Copy formatted results via ⌘⇧C, download as a .yaml or .json file, or generate a gzip-compressed shareable URL for team troubleshooting.

YAML Converter Features

• ✓

  Bidirectional JSON ↔ YAML Conversion: Automatically detects input syntax and converts seamlessly between JSON and YAML with zero configuration required.

• ✓

  YAML 1.2 Specification Compliance: Full compatibility with modern YAML 1.2 standards while safely parsing legacy YAML 1.1 constructs used across Kubernetes and Ansible.

• ✓

  Multi-Document Stream Support: Seamlessly parses and serializes multi-document YAML files delimited by triple dashes (---), converting them into clean JSON arrays.

• ✓

  Anchor (&) and Alias (*) Resolution: Automatically resolves YAML reference anchors, aliases, and merge keys (<<:) during JSON conversion for complete object expansion.

• ✓

  Precision Syntax Error Highlighting: Pinpoints syntax violations, bad indentation, unclosed quotes, and duplicate keys with exact line and column numbers alongside actionable fix hints.

• ✓

  Configurable Indentation Engine: Customize output structure with 2-space, 4-space, or 8-space indentation to adhere to Prettier, ESLint, or organizational style guides.

• ✓

  Deterministic Key Sorting: Recursively sorts dictionary and mapping keys alphabetically to eliminate noisy Git diffs across CI/CD configuration updates.

• ✓

  Custom Scalar Quote Formatting: Select between plain (unquoted), single-quoted ('...'), or double-quoted ("...") string scalar output to prevent unexpected type coercion.

• ✓

  Block vs. Flow Style Toggle: Switch between human-readable indented block style and compact inline flow style ({ key: value }) for JSON-like YAML output.

• ✓

  Folded & Literal Scalar Handling: Preserves and formats multiline string blocks using literal (|) and folded (>) operators with configurable line-wrapping limits.

• ✓

  DevOps & Infrastructure Presets: Built-in templates for Kubernetes Deployments, Services, ConfigMaps, Docker Compose services, and GitHub Actions CI pipelines.

• ✓

  Drag-and-Drop File Support: Effortlessly load and convert local .json, .yaml, and .yml files with instant client-side file reading.

• ✓

  Power User Keyboard Shortcuts: Accelerate workflow with ⌘↵ (Convert), ⌘⇧Y (Force JSON→YAML), ⌘⇧J (Force YAML→JSON), ⌘⇧V (Validate), and ⌘⇧C (Copy).

• ✓

  100% Client-Side Privacy: All parsing, transformation, and validation execute strictly inside browser memory with zero telemetry or network transmission.

Supported Formats & Dialects

The YAML Converter supports 6 syntax formats and dialects for accurate parsing and processing.

YAML 1.2 Core Specification

The modern YAML standard defining strict JSON superset compatibility, standardized boolean tokens (true/false), integer radix formats, and clean scalar parsing.

Kubernetes Multi-Document Manifests

Multi-resource YAML streams separated by triple dashes (---) containing Deployments, Services, Ingresses, and ConfigMaps converted to structured JSON arrays.

Docker Compose Specification

Container orchestration YAML defining multi-container service topologies, environment variable mappings, volume mounts, port bindings, and bridge networks.

GitHub Actions & CI/CD Pipelines

Workflow YAML configurations featuring matrix build strategies, conditional expressions (${{ ... }}), runner steps, secret references, and event triggers.

YAML Anchors & Merge Key Inheritance

DRY configuration structures utilizing anchor definitions (&base), alias references (*base), and dictionary merge overrides (<<:) expanded into canonical data.

Standard RFC 8259 JSON Payloads

Standard JavaScript Object Notation format parsed from REST API endpoints, configuration files, and database exports ready for conversion to clean YAML.

Frequently Asked Questions

How does client-side YAML ↔ JSON parsing and AST conversion work in DevFlow?

DevFlow utilizes a high-performance client-side parser to tokenize YAML and JSON inputs into Abstract Syntax Trees (AST). When converting JSON to YAML, the parser traverses JavaScript object and array hierarchies, applying specified indentation, quote styles, and block formatting. When converting YAML to JSON, the parser handles token streams, validates indentation hierarchies, resolves anchors and merge keys, and serializes the resulting data structure into RFC 8259 JSON entirely inside your browser memory without network calls.

How does the converter handle YAML 1.2 versus legacy YAML 1.1 boolean coercion (the "Norway Problem")?

In YAML 1.1, unquoted tokens such as "NO" (the ISO country code for Norway), "yes", "on", or "off" were implicitly coerced into boolean values (false/true). YAML 1.2 resolved this by restricting boolean literals strictly to true and false, treating "NO" and "yes" as plain strings. DevFlow follows the YAML 1.2 specification, preventing accidental boolean type coercion while providing configurable quote styles (single, double, or plain) to ensure strings remain strings across downstream tooling.

How are multi-document YAML streams (separated by `---`) converted into JSON structures?

YAML documents separated by triple dashes (---) represent distinct serialized payloads in a single stream, a pattern ubiquitous in Kubernetes manifests and Helm charts. DevFlow parses all documents in the stream sequentially. In JSON conversion mode, multi-document files are automatically aggregated and structured as a root-level JSON array containing each individual document object in order.

How does the parser resolve YAML anchors (`&`), aliases (`*`), and merge keys (`<<`) during conversion?

YAML anchors (&anchorName) mark nodes for reuse, while aliases (*anchorName) reference them elsewhere in the document. Merge keys (<<: *anchorName) inject all key-value pairs from an anchored mapping into the current mapping. During conversion to JSON, DevFlow fully evaluates and dereferences these pointer structures, expanding shared configurations into standalone, self-contained JSON objects.

How does the YAML syntax validator pinpoint indentation errors and line/column positions?

The validator parses the input through a strict tokenizer that tracks byte offsets and newline boundaries. If an indentation mismatch, malformed mapping delimiter (such as a missing space after a colon), or unclosed quotation occurs, the parser extracts the exact 1-based line and column number, highlighting the problematic token and supplying actionable suggestions (e.g., checking for tabs vs spaces or missing closing brackets).

What is the difference between literal block scalars (`|`) and folded block scalars (`>`) in YAML?

Both block scalar styles allow multiline strings without requiring manual newline escape sequences (\n). The literal block scalar (|) preserves all line breaks verbatim, making it ideal for shell scripts, private keys, or formatted markdown. The folded block scalar (>) replaces single line breaks with spaces while preserving empty lines as paragraph separators, making it ideal for long sentences or wrapped configuration descriptions.

How does sorting keys alphabetically improve Git version control and CI/CD workflow diffs?

When multiple developers or automated scripts edit YAML and JSON configuration files, arbitrary object key ordering produces noisy Git diffs and unnecessary merge conflicts. Enabling the "Sort Keys" option recursively alphabetizes dictionary keys at every nesting level, generating deterministic, normalized output that highlights only genuine functional modifications in pull requests.

Can DevFlow convert complex Kubernetes manifests and Docker Compose files to JSON?

Yes. DevFlow fully supports nested Kubernetes structures (Deployments, StatefulSets, Custom Resource Definitions, ConfigMaps) and Docker Compose service configurations. It accurately parses nested array sequences, environment variable key-value maps, volume mount specifications, and multi-resource stream delimiters (---) without losing data types or structural hierarchy.

How does quote styling (plain, single, double) and flow vs block style formatting work in YAML generation?

When serializing to YAML, DevFlow allows you to customize the scalar quote style: "plain" omits quotes where safe, "single" wraps strings in single quotes (escaping internal single quotes), and "double" wraps strings in double quotes (enabling standard C-style escape sequences). The "flow" style formats objects and arrays inline ({ key: value }, [1, 2]), whereas "block" style produces clean, multiline indented structures.

Why does YAML forbid tab characters for indentation and how does DevFlow handle them?

YAML forbids horizontal tab characters (\t) for indentation because different text editors, IDEs, and terminals interpret tab stops with variable column widths (typically 2, 4, or 8 spaces), leading to ambiguous AST nesting hierarchies. DevFlow flags tab characters as syntax violations during validation and formats all output using uniform space indentation (2, 4, or 8 spaces).

Related Developer Tools

• JSON FormatterPrettify, minify, and validate JSON data instantly.
• GitHub Actions ValidatorValidate, format and summarize GitHub Actions workflow YAML files against official schemas.
• Kubernetes YAML ValidatorValidate, lint, and format Kubernetes manifests against structure rules, deprecated APIs, and security best practices.
• Docker Compose to KubernetesConvert docker-compose.yml to Kubernetes Deployment, Service, ConfigMap, and PVC manifests.
• Dockerfile LinterLint, validate, format, and optimize Dockerfiles with Hadolint-compatible rules, security checks, and multi-stage analysis.
• Env File Parser & ConverterParse, validate, and convert .env files between JSON, YAML, Docker, and Kubernetes formats.
• TOML ConverterConvert between TOML and JSON formats with syntax validation, key sorting, and auto-direction detection.
• JSONL ConverterConvert between JSONL (JSON Lines / NDJSON) and standard JSON arrays with auto-detection.
• JSON to TypeScript & Schema GeneratorGenerate TypeScript interfaces, Zod schemas, and Valibot schemas from JSON.
• JSON to TypeScriptConvert JSON to TypeScript interfaces or type aliases instantly.
• JSON Repair ToolRepair and fix malformed JSON data from AI outputs, API responses, and copy-paste.
• MCP Schema ValidatorValidate, format, test, and debug Model Context Protocol (MCP) server schemas and tool definitions.
• XML FormatterFormat, beautify, validate, minify, and convert XML to JSON with syntax highlighting.
• Text Diff CheckerCompare two text blocks and highlight exactly what changed.
• Base64 Encode/DecodeEncode and decode Base64 strings, files, and data URIs instantly.
• HTML FormatterFormat, minify, and validate HTML with attribute sorting and template support.