Configuration formatting
Check syntax, inspect table locations and format without rebuilding your file from plain objects.
Content stays in this browser. Input is not uploaded, executed, saved or added to a URL.
Sorting is off by default. Contiguous key groups are sorted; attached comments follow keys while group headings stay in place. Arrays and table order stay unchanged.
TOML 1.0.0 · dprint TOML 0.8.0 · toml-eslint-parser 1.0.3. Syntax validation does not check application schemas.
500,000 UTF-16 input units / 2 MB UTF-8; 50,000 nodes, depth 100, 2 million output characters; 5-second task timeout.
Enter TOML or run a check.
A TOML formatter should make a configuration easier to read without erasing the notes that explain it. This workbench keeps formatting in a separate result, so you can inspect whitespace and optional key sorting before replacing your input.
Use the TOML beautifier for readable project settings, or the TOML validator when you only need a syntax check. When you format TOML online, tables, repeated array tables and multiline text need a real parser rather than a line-by-line rewrite.
Readable configuration with its explanations intact
The TOML formatter retains standalone and trailing comments instead of discarding them during object serialization. Optional sorting moves an entry’s leading notes with that entry; blank-line-separated groups keep their own headings.
Navigation lists each real table header, including repeated array-table instances, with its input location. A bracketed line inside a triple-quoted string is data, so it never becomes a false navigation target.
Three controls that change how you work
Validate only cancels any pending automatic task and checks the current source without creating an exportable formatted result. It still provides table navigation. Edit the input to resume automatic formatting, or turn automatic mode off and use Format or Ctrl/Cmd+Enter.
Click a table entry or the first reported error to focus its line and column in the input. Repeated array tables remain separate entries. Long navigation lists show 50 headers at a time; output downloads are never truncated to that display limit.
Use result previews the formatted text before it becomes input. Example, Clear and a local UTF-8 file also use a replacement preview with line counts. Apply retains one Undo that restores input, options, result and any previous error; edits immediately disable stale exports.
Control presentation while keeping TOML data types
A syntax-tree formatter handles comments, quoted keys, multiline strings and inline tables. A preservation guard compares parsed values and comment content before accepting output; failures stop the operation rather than exposing a partial file.
Keep the original order by default, or sort contiguous key groups separated by blank lines. Attached leading and trailing comments move with their entries. Array elements, inline-table keys, ordinary table order and array-table instance order are not reordered.
Choose two spaces, four spaces or tabs, a preferred width of 80, 100 or 120 columns, and LF or CRLF output. Width is a layout preference, not a guarantee that every string or comment fits. String values retain their content even when layout changes.
Formatting runs in a cancellable browser worker with a five-second limit. Automatic mode waits 350 ms after an edit; manual mode exposes Format. The clipboard and UTF-8 download use the same current output text, and neither can export an outdated result.
Know what a successful check actually establishes
Comments, specification and project files
Yes. The TOML formatter parses the source before formatting and checks preservation before accepting the result. Validate only offers a separate syntax check without formatted output. An error remains visible with a clickable location, and editing invalidates all previous exports.
This page explicitly accepts TOML 1.0.0 through toml-eslint-parser 1.0.3 and formats with dprint TOML 0.8.0. The version is visible beside the options. Newer TOML 1.1 syntax is outside the declared contract even if another tool accepts it.
Yes, accepted output retains comment content. Unlike converting to a plain object and serializing it again, this TOML formatter uses a syntax-tree formatter and a preservation guard. Sorting can move a comment with its key, while whitespace and blank-line layout may change.
It can format TOML 1.0 syntax in pyproject.toml and Cargo.toml within the documented limits, preserving their values and comments. It does not validate Python packaging metadata, Rust dependencies or application schemas, and Cargo formatting conventions are disabled.
Processing runs locally in a browser worker. The page loads its formatting engine as a site asset; your source is not included in that request. The TOML formatter creates a new download only when you request it, leaving your original file untouched.
Found a comment or table layout we should check?
Use the TOML formatter to inspect comments, table locations and optional sorting before replacing a project configuration.
Syntax success does not replace your project’s own validation.