TOML Formatter & Validator
Validate, format and convert TOML in one place
Runs 100% in your browser — nothing is ever uploaded.
What is TOML Formatter?
Paste any TOML document to validate its syntax and re-serialize it in a clean canonical layout. Parse errors are reported with a clear message so you can fix Cargo.toml, pyproject.toml or config files fast — and one extra click converts the TOML to JSON for use in scripts.
How to use TOML Formatter
- Paste your TOML into the input box or click “Load sample” to try it.
- Adjust the options in the toolbar if needed (root name, format, delimiter …).
- Click the convert button — the TOML/JSON output appears instantly in the output pane.
- Copy the result with one click or download it as a file.
ConvertLab FAQ
Is the TOML formatter free?
Yes — 100% free, no signup, no limits, no watermarks. Use it as often as you like.
Can I also convert TOML to JSON?
Yes — next to the format button there is a “TOML → JSON” action that parses your document and outputs pretty-printed JSON, handy for feeding TOML configs into tools that only read JSON.
Is my data uploaded to a server?
No. Everything runs entirely in your browser with JavaScript — your data never leaves your device, which makes the tool safe even for confidential files.
Are these converters free?
Yes — every ConvertLab tool is 100% free with no signup, no limits and no ad walls.
Is my data uploaded anywhere?
No. All conversions (JSON, CSV, XML, YAML, INI, .env) run entirely in your browser. Nothing ever leaves your device.
Do these tools work offline?
Yes — once the page is loaded, every converter works without an internet connection.