Free online INI to TOML converter

1. Source format: INI

INI is a simple configuration file format used to store settings in plain text. It is common in Windows applications, older desktop software, games, and small utilities. An INI file usually contains sections in square brackets and key-value pairs such as name=value. It is easy for both humans and programs to read, which makes it popular for lightweight configuration.

2. Target format: TOML

TOML stands for Tom's Obvious, Minimal Language. It is a modern configuration format designed to be easy to read and unambiguous. TOML is widely used in software projects, especially in the Python, Rust, and general developer tooling ecosystems. Compared with INI, TOML supports richer data types such as strings, integers, booleans, arrays, dates, and nested tables. Its main advantages are clearer structure, better type handling, and stronger consistency for complex configuration.

3. How to perform the conversion

There is no universal one-click conversion because INI and TOML are not fully equivalent. The best approach is usually to convert the file manually or with a script, then verify the result. If your INI file is simple, you can also use the built-in converter on 101convert.com for free without installing any software.

Step 1: Inspect the INI file and identify its structure. Look for sections like [database] and keys such as host=localhost. Note any values that should become numbers, booleans, or arrays in TOML.

Step 2: Map INI sections to TOML tables. For example, [database] in INI usually becomes [database] in TOML as well. Nested section names such as [server.ssl] may become nested TOML tables.

Step 3: Convert values to proper TOML types. Strings should be quoted, numbers should remain numeric, and booleans should use true or false. For example, port=5432 becomes port = 5432, and enabled=yes should usually become enabled = true if that is the intended meaning.

Step 4: Rewrite the file in TOML syntax. A simple example:

[database]
host = "localhost"
port = 5432
enabled = true

Step 5: Validate the TOML file with a parser or your application. If you use a desktop editor such as Visual Studio Code, Notepad++, or Vim, syntax highlighting and TOML extensions can help catch mistakes. In many cases, the safest workflow is to convert the file, then test the application that will read it.

If you prefer automation, a small script can help when many INI files need conversion. For example, a Python script can read INI data and write TOML, but you should still review the output because some INI features do not translate directly.

4. Notes on quality, compatibility, and limitations

INI to TOML is not always lossless. INI files often allow duplicate keys, loose typing, comments in different styles, and application-specific conventions. TOML is stricter, so some INI files may need manual cleanup before they become valid TOML.

Common limitations include:

• Duplicate keys in INI may not be allowed in TOML.
• Implicit types in INI must be made explicit in TOML.
• Flat key names using dots or special separators may need restructuring.
• Comments and formatting may not carry over exactly.

For simple configuration files, conversion is usually straightforward. For complex or application-specific INI files, expect to do some manual editing after conversion. Always test the resulting TOML file in the target application or parser to confirm that the settings behave as expected.