About INI/Config Validator

Validate INI and config file syntax with line-by-line analysis. Part of the DevTools Surf developer suite. Browse more tools in the Data / SQL collection.

Use Cases

• Validate PHP application config files (php.ini, .env.ini) before deployment.
• Check ansible.cfg, Terraform backend configs, or other INI-based tool configurations for syntax errors.
• Verify Windows registry export (.reg) files that use an INI-like format.
• Parse and validate game config files that use INI format (common in Unity and Unreal projects).

Tips

• Check that section names contain no brackets or whitespace — [section name] is valid but [[nested]] causes parse errors in most INI parsers.
• Validate both the INI syntax and the expected key presence simultaneously by enabling key-schema mode.
• Use line-by-line error output to pinpoint issues in large config files without scrolling through hundreds of lines.

Fun Facts

• The INI file format originated in MS-DOS and early Windows (late 1980s). win.ini and system.ini were the primary Windows 3.x configuration files — both have been superseded but the format persists widely.
• There is no formal specification for INI files — different parsers disagree on multi-line values, comment characters (# vs. ;), duplicate keys, and section inheritance. Python's configparser, PHP's parse_ini_file, and Windows registry INI all behave differently.
• Git's own configuration file (.git/config) is an INI-derivative format — it extends the format with subsections like [branch "main"] and multi-valued keys.

FAQ

What counts as a valid INI file?

Sections in square brackets, key=value pairs, and comments starting with # or ;. The validator follows Python configparser behavior by default, which is the most widely accepted reference implementation.

Does it support multi-line values?

Multi-line values (indented continuation lines) are validated if enabled. Some parsers reject them; the validator shows whether your file passes strict or lenient modes.

Can it detect duplicate keys?

Yes — duplicate keys within the same section are flagged as warnings. Whether they are errors depends on the parser; most take the last value, some raise exceptions.