Inspect a TOML config as JSON to debug it

Is that dotted key landing where you think it is? Converting pyproject.toml or Cargo.toml to JSON makes the resolved structure obvious.

Tools used in this guide

TOML ↔ JSON converter
YAML ⇄ JSON converter
JSON formatter

The job

TOML's dotted keys and [table] headers are friendly to write and annoying to reason about. Seeing the same file as flat JSON shows exactly which object each key lands in.

Convert and read

Paste the TOML, run TOML→JSON. Sections nest into objects, arrays stay arrays, datetimes become strings. The reverse direction rebuilds TOML with [section] headers for nested objects.

Integers (incl. 0x/0o/0b and underscores), floats, nan/inf, booleans and inline tables are all handled.
[[array-of-tables]] is not supported — files using it need a full TOML parser.

Where it helps

Spotting a misplaced [tool.black] vs [tool.black.settings], or checking what a dotted a.b.c = 1 produced. For shipping conversions remember JSON round-trips don't preserve comments — keep the TOML as the source of truth.