How to Convert Config Files Between YAML, JSON, TOML, and INI Online

Working with multiple configuration file formats is common in software development. Different tools and frameworks prefer different formats — Docker uses YAML, npm uses JSON, Rust uses TOML, and legacy systems use INI. This guide shows you how to convert between config formats online using fixie.tools — a free tool that handles all major configuration file formats instantly.

Step 1: Open the Config File Converter

Go to fixie.tools/config-convert in your browser. No signup or installation needed.

Step 2: Paste or Upload Your Config

Paste your configuration file content into the input area, or upload a config file directly. The tool auto-detects the input format (YAML, JSON, TOML, or INI) based on the content structure.

Step 3: Select the Target Format

Choose the output format you need: YAML, JSON, TOML, or INI. The converter handles nested structures, arrays, and data types correctly across formats.

Step 4: Review and Copy the Output

The converted config appears instantly in the output panel. Review it for correctness — the tool preserves data types and structure. Copy the output or download it as a file.

Frequently Asked Questions

Is the config converter free?
Yes, completely free with no signup and no limits on conversions.
Which config formats are supported?
The tool converts between YAML, JSON, TOML, and INI formats. It handles nested structures, arrays, and various data types.
Does it preserve comments?
Comments are not preserved during conversion since not all formats support them equally. JSON has no comment syntax, while YAML and TOML do. Add comments back after conversion if needed.
Can I convert complex nested configs?
Yes. The tool handles deeply nested structures and arrays. Note that INI format has limited nesting support, so complex nested configs may lose some structure when converting to INI.

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