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TOML Validator

Validate TOML for common syntax issues in configs, package files, and app settings.

Tool

Use this TOML validator to check whether TOML is structurally valid before using it in apps, package files, scripts, or configuration workflows. It is useful when broken TOML can cause config errors, startup failures, or confusing debugging sessions.

About this tool

Use this TOML validator to check whether TOML is structurally valid before using it in apps, package files, scripts, or configuration workflows. It is useful when broken TOML can cause config errors, startup failures, or confusing debugging sessions.

Use toml validator when you need a fast browser-based result without extra setup. It works well for quick checks, one-off tasks, and routine formatting or calculation work.

Learn more

Why use this tool

How to use

  1. Paste the TOML into the input box
  2. Click Run Tool to validate the content
  3. Review whether the TOML is valid or invalid
  4. Fix broken sections, arrays, or assignments if needed
  5. Run it again after changes to confirm the result

Examples

Example

Input

title = "Demo"
enabled = true

Output

Valid TOML.

A simple TOML file with valid assignments passes validation.

Example

Input

[server
port = 3000

Output

Invalid TOML.

Broken section syntax should fail validation.

Common errors

Broken table or section syntax

Fix: Make sure every section header is complete, for example [server] instead of [server.

Malformed arrays or mixed value formatting

Fix: Check commas, brackets, and value quoting inside arrays.

The user expects formatting instead of validation

Fix: Use TOML Formatter when readability is the main goal.

FAQ

What does a TOML validator do?

A TOML validator checks whether TOML syntax is valid and structurally readable by a TOML parser.

Why use TOML Validator?

It helps catch syntax problems before broken TOML causes config or application errors.

What is the difference between TOML Validator and TOML Formatter?

TOML Validator checks correctness, while TOML Formatter improves readability.

Can valid TOML still contain the wrong values?

Yes. TOML can be syntactically valid but still contain incorrect settings for your app.

When should I use TOML to JSON after validation?

Use TOML to JSON after validation when you want to inspect or reuse the data in JSON-based tools or workflows.

Use cases

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