What is TOML?

Full name

Tom’s Obvious Minimal Language

Kind

structured data

File extension

.toml

MIME type

application/toml

Developer / standard

Tom Preston-Werner · 2013

Compression

none

Quality model

Lossless / not lossy

Container

No / single bitstream typical

Common codecs

—

Technical sources

—

Transparency

Not supported

Animation

No (still / non-animated typical use)

Typical size

Tiny for most configs

Browser support

Convert privately in Format Convertly; open in any text editor

Compatibility

First-class in Rust/Cargo and many modern CLIs; convert to JSON when a web service or legacy tool only accepts JSON

TOML compression: none. Lossless (or non-destructive packaging) keeps reconstructable data — size savings come from packing efficiency, not throwing detail away. Typical size profile: Tiny for most configs. Quality note: Lossless structured text for configuration

Quality: Lossless structured text for configuration

Typical size: Tiny for most configs

TOML does not support an alpha channel. Convert to PNG, WebP, AVIF, or SVG when you need transparent backgrounds.

TOML is a still-media or non-animated format in typical use. Use GIF, APNG, video, or animated WebP when you need motion.

Usually none beyond encoding/BOM — structure is the content. Comments allowed in YAML/TOML.

• Cargo and Rust tooling
• Modern CLI app config
• Human-edited service settings
• Replacing ad-hoc INI with clearer types

• Deeply nested documents better as JSON
• End-user documents
• Binary data
• Teams standardized only on YAML without tooling

• Readable tables
• Typed values
• Less ambiguous than some YAML
• Great for app config

• Younger ecosystem than JSON/YAML in places
• Not a wire API default
• Easy to break with duplicate keys depending on parser
• Not for prose documents

First-class in Rust/Cargo and many modern CLIs; convert to JSON when a web service or legacy tool only accepts JSON

Browsers: Convert privately in Format Convertly; open in any text editor

• Format Convertly
• Cargo
• VS Code
• Neovim

• Desktop and mobile browsers for conversion
• Modern desktops
• Phones and tablets with compatible apps

Edit TOML in VS Code or any text editor with syntax highlighting. Validate before deploy — a missing quote can break Cargo or CLI startup.

Convert TOML to JSON in Format Convertly when the next tool in your pipeline needs JSON — configuration stays local in the browser.

Incoming conversions strengthen the TOML cluster — e.g. JPG → TOML, PNG → TOML.

Decision pages that cite TOML — the next hop after a vs comparison.

Tools extend the format graph beyond one-off conversion — compression, metadata, and utilities for real workflows.