Taplo

Free plan APIExtensionLinuxMacWindows

What Taplo is

Taplo is a free toolkit for checking, formatting and querying TOML documents, with support for TOML 1.0.0. Its validator checks syntax and semantic issues such as duplicate keys, and can validate against JSON Schema Draft 4. The formatter can edit files in place or work through standard input and output; by default, it stops at syntax errors. The CLI converts TOML to JSON and retrieves values through query expressions. Taplo also supports schema catalogs such as JSON Schema Store, which can match schemas to files by name. Installation options include precompiled releases, Cargo, Homebrew, NPM and Docker; precompiled releases are listed for Linux, macOS and Windows on several architectures. The TOML language server uses standard input/output or TCP, but does not support multiple TCP clients. It is excluded from default builds and unavailable in the NPM installation. The Visual Studio Code extension offers editing tools, but is marked as a preview that may have bugs or crash. No paid tiers or usage limits are stated.

Who it suits

Taplo suits developers and others working with TOML who want validation, formatting, queries or JSON conversion. Its CLI, library API and editor extension offer several ways to use it.

What it does well

Supports TOML 1.0.0 and JSON Schema Draft 4.
CLI converts TOML to JSON and extracts values.
Formatter can edit files in place.
Precompiled releases are listed for Linux, macOS and Windows.

What to know first

Language server is excluded from default builds.
Language server is unavailable in the NPM installation.
VS Code extension preview may contain bugs or crash.
Multiple TCP clients are not supported.

Plans

Plan	Billed and limits	Price
Taplo	No paid tiers or usage limits are stated on the official pages reviewed.	Free

As taplo.tamasfe.dev lists them, read 4 Oct 2026. The maker's own page has the final word.

Getting started

Open the Taplo website.
Choose a CLI installation route such as a precompiled release, Cargo, Homebrew, NPM, or Docker.
For precompiled releases, choose a listed build for Linux, macOS, or Windows.
Use the CLI to validate, format, convert, or query TOML documents.
For Visual Studio Code features, install the Even Better TOML extension.

Verdict

Taplo brings TOML validation, formatting and queries into a free toolkit with multiple installation options. Note the language server's build and NPM limits, and the preview status of its Visual Studio Code extension.

Questions

Does Taplo cost anything?

Taplo is free, and no paid tiers or usage limits are stated on its official pages reviewed.

Which operating systems are supported?

Precompiled releases are listed for Linux, macOS, and Windows on several architectures. Installation options also include Node.js and Docker.

Is Taplo open source?

Yes. Taplo has an open source license model.

What can Taplo do with TOML files?

It validates and formats TOML, converts TOML to JSON, and extracts values using query expressions.

Can I use Taplo in Visual Studio Code?

The Even Better TOML extension provides highlighting, validation, folding, navigation, renaming, formatting, and JSON Schema completion. Its listing describes it as a preview that may contain bugs or crash.

Are there language server installation limits?

The language server is excluded from default builds and unavailable in the NPM installation. It communicates over standard input/output or TCP, but does not support multiple TCP clients.

Facts from Taplo's own pages

Conversion and queries: The CLI converts TOML to JSON and extracts values using query expressions. · taplo.tamasfe.dev, 4 Oct 2026
Editor integration: The Even Better TOML Visual Studio Code extension offers syntax highlighting, validation, folding, navigation, renaming, formatting, and JSON Schema completion. · marketplace.visualstudio.com, 4 Oct 2026
Embedding: Taplo aims to be embeddable in software across programming languages and environments. · taplo.tamasfe.dev, 4 Oct 2026
Extension status: The Visual Studio Code listing describes the extension as a preview that may contain bugs or crash. · marketplace.visualstudio.com, 4 Oct 2026
Formatting: The formatter can edit files in place or use standard input and output, and it stops on syntax errors by default to avoid destructive edits. · taplo.tamasfe.dev, 4 Oct 2026
Install options: The CLI is available as precompiled releases, through Cargo, Homebrew, NPM, and Docker. · taplo.tamasfe.dev, 4 Oct 2026
Language server: The TOML language server communicates over standard input/output or TCP; multiple TCP clients are not supported. · taplo.tamasfe.dev, 4 Oct 2026
Language server limit: The language server is excluded from default builds and is unavailable in the NPM installation. · taplo.tamasfe.dev, 4 Oct 2026
Purpose: Taplo is a TOML toolkit for validating, formatting, and querying TOML documents. · taplo.tamasfe.dev, 4 Oct 2026
Schema integration: Taplo supports schema catalogs such as JSON Schema Store for retrieving schemas and matching them to files by name. · taplo.tamasfe.dev, 4 Oct 2026
Security and trust: The official pages reviewed do not state security certifications or compliance claims. · taplo.tamasfe.dev, 4 Oct 2026
Supported operating systems: Precompiled releases are listed for Linux, macOS, and Windows on several architectures. · taplo.tamasfe.dev, 4 Oct 2026
TOML support: Taplo supports TOML 1.0.0. · taplo.tamasfe.dev, 4 Oct 2026
Validation: Taplo validates TOML syntax and semantic errors such as duplicate keys, and supports JSON Schema Draft 4 validation. · taplo.tamasfe.dev, 4 Oct 2026

Where Taplo stands on Freedom251

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