Withdata DataFileConverter converts YAML (*.yaml, *.yml) files to JSON locally — single file, batch, or merge multiple YAML files into one JSON. Nested YAML mappings are flattened into dotted column names. 100% local, secure, and cross-platform.

YAML is a human-readable data serialization format.

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Why Choose Withdata YAML to JSON Converter?

🔒 100% Local & Secure

YAML files are read and converted on your own computer. Nothing is uploaded to any cloud server.

⚡ Fast Streaming Conversion

Large YAML files are processed in streaming mode with low memory usage — millions of rows within a minute.

📁 Batch & Merge

Batch convert many YAML files to JSON files, or merge multiple YAML files into one JSON.

🔄 Nested YAML → Dotted Columns

Nested mappings become address.city-style column names; sequences and block scalars are expanded automatically.

🖥 Windows, macOS, Linux

Native builds for Windows, macOS and Linux, with a step-by-step GUI wizard and a command line interface.

⏱ CLI & Scheduled Tasks

Save a conversion session and run it automatically from Windows Task Scheduler or crontab.

Full Feature Comparison

Feature	Supported details
Input source	Local YAML (`.yaml`, `.yml`), batch YAML, merged YAML
Output format	JSON object array, plain JSON array, or JSON Lines (one object per line)
Conversion mode	Single file · merge many YAML files into one JSON · batch (one to one)
Running mode	GUI wizard · command line · scheduled tasks
Source options	Dotted column names for nested mappings, row source, encoding
Output options	Column mapping, encoding, date format, empty value handling
Platform	Windows, macOS, Linux (native, 64-bit)

All YAML to JSON Conversions You Need

Single YAML file → JSON file, step by step in the GUI wizard
Batch convert multiple YAML files → multiple JSON files
Convert YAML to JSON in the command line, and run it as a scheduled task
All YAML conversion tools and all JSON conversion tools

YAML to JSON Notes

A top-level sequence of mappings is read as a table — each mapping becomes one row.
Nested mappings are flattened into dotted column names, e.g. address.city, address.zip.
Block scalars (|, >) are read as multi-line text.
Both .yaml and .yml files are accepted; UTF-8 (with or without BOM) is detected automatically.
Not supported: anchors and aliases (& / *), tags (!!) and multi-document files (---).

How to Convert YAML to JSON (4 Steps)

Open Withdata DataFileConverter and select YAML as the input type and JSON as the output type.
Load your YAML data — a single file, a folder / list of files for batch conversion, or several files to merge into one.
Check the preview table, then adjust the source options and the output options.
Click Convert — the JSON output is written in seconds. Save the session if you want to run it again from the command line.