Drop in a YAML, TOML, .env, or INI file. Checks real syntax rules per format — tabs in YAML indentation, unterminated TOML strings, unquoted .env values with spaces, malformed INI sections — and reports exactly which line is wrong and why. This validates; it doesn't rewrite your structure or guess at intent.
If you're here because something threw one of these, this tool shows you exactly what's wrong and how much is recoverable:
This is a validator, not a repair tool — unlike JSON / XML Repair, it doesn't rewrite your structure or guess at what a broken key/value was supposed to be, because config formats carry too much application-specific meaning to safely infer. The only automatic fix offered is a "cleaned copy" that trims trailing whitespace and, for YAML, converts leading tabs to spaces (both fully unambiguous, deterministic fixes). Checks are syntax-level only — none of these formats have a universal schema, so a file can pass every check here and still be rejected by the specific application that reads it (an unknown key, wrong data type, missing required field). TOML validation covers basic and array tables, inline tables, and basic/literal strings, but not every edge case in the full spec (e.g. deeply nested inline tables, all datetime formats). YAML validation is syntax-level (indentation, tabs, quoting, duplicate top-level keys) — it does not implement a full YAML 1.1/1.2 parser, so some valid-but-exotic constructs (anchors, tags, multi-document streams) aren't specially understood, and won't be flagged as wrong just because they're unfamiliar. Duplicate-key detection is per-section/per-nesting-level and best-effort, not a guarantee.