Free online TOML editor and validator. Edit, validate and format TOML config files in real-time. Supports TOML to JSON and JSON to TOML conversion. Client-side processing, no data uploaded. · Client-side processing · Your data never leaves your device
Zero dependencies·Works offlineTOML (Tom's Obvious Minimal Language) is a minimal configuration file format created by GitHub co-founder Tom Preston-Werner in 2013. TOML is designed to be easy to read and write while mapping unambiguously to hash tables. It's simpler and more explicit than YAML (no indentation traps) and more readable than JSON (supports comments). TOML has become the preferred configuration format for many projects, including Rust's Cargo.toml, Python's pyproject.toml, Hugo's config.toml, and more.
Key-value pairs: key = "value", strings must be quotedTables: [table-name], equivalent to JSON objectsInline tables: name = {first = "Tom", last = "Preston-Werner"}Array of tables: [[products]], equivalent to JSON arrays of objectsArrays: colors = ["red", "yellow", "green"]Strings: basic ("..."), multiline ("""..."""), literal ('...'), multiline literal ('''...''')Numbers: integers (42), floats (3.14), +/- infinity (inf), NaN (nan)Booleans: true or falseDatetime: 1979-05-27, 07:32:00, 1979-05-27T07:32:00ZComments: from # to end of lineEdit TOML: Type or paste TOML content in the editor. The editor shows line count in real-time. Follow TOML syntax rules: string values must be quoted, table names wrapped in square brackets, key-value pairs connected with equals sign.
Validate TOML: Click "✅ Validate" to check TOML syntax. If errors exist, the status bar shows red error messages with line numbers. Fix errors and validate again.
TOML to JSON: Click "🔄 TOML→JSON" to convert TOML to JSON format. The result appears in the output area for viewing the data structure or programmatic use.
JSON to TOML: Enter JSON content in the editor, then click "🔄 JSON→TOML" to convert JSON to TOML format. Nested JSON objects become TOML tables.
Rust project configuration: Cargo.toml is the core config file for Rust projects, defining project name, version, dependencies, etc. Use this tool to quickly validate and edit Cargo.toml.
Python project configuration: PEP 518 specifies pyproject.toml uses TOML format. Modern Python projects (Poetry, Flit, etc.) store build and dependency configs in pyproject.toml.
Static site generators: Hugo uses config.toml for site configuration. This tool helps validate Hugo configs, preventing build failures from TOML syntax errors.
A: TOML (Tom's Obvious Minimal Language) is a minimal configuration file format created by Tom Preston-Werner. It's designed to be easy to read and write while mapping unambiguously to hash tables. Widely used in Rust's Cargo.toml, Python's pyproject.toml, and other configuration files.
A: TOML is simpler and more explicit than YAML, without YAML's indentation traps and complex features; more readable than JSON, with comment support. TOML is best for config files, JSON for data exchange, YAML for complex structured configs. TOML has a stricter type system and simpler, more reliable parsing.
A: Supports all features of the TOML v1.0 specification, including: key-value pairs, tables, inline tables, array of tables, arrays, strings (basic/multiline/literal), integers, floats, booleans, datetime, and more.
A: Completely safe. This tool is a pure front-end implementation. All parsing and formatting operations are performed locally in your browser. TOML content is never uploaded to any server. All data is cleared when you close the page.
A: Enter or paste TOML content in the editor, then click the "TOML→JSON" button to convert TOML to JSON format. The result is displayed in the output area and can be copied. If there are syntax errors, the error location will be shown first.
🔒 No data uploaded to servers. This tool runs entirely in your browser. All TOML parsing and formatting operations are performed on your device. Your configuration content is never sent to any server over the network. Data is cleared when you close the page. Use with confidence.