What Is a .toml File? .toml Format, MIME & How to Open

Quick facts

Extension.toml

File typeTOML Configuration

MIME typeapplication/toml

CategoryData & Text

Charset—

CompressibleYes

Format familytoml

What is .toml

What is a .toml file?

A .toml file is a TOML Configuration — Minimal configuration file format with explicit structure.

In the mime-db registry it maps to application/toml, and it is marked as compressible. When serving .toml over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to application/toml and is used by TOML among others — and is delivered over HTTP via the Content-Type header.

How to open .toml files

Use VS Code or Rust to open and edit .toml files.
Any text editor (Notepad, VS Code) can inspect the raw content as text.

Developer info

When served over HTTP, responses should set the following header:

Content-Type: application/toml

Common software that reads/writes .toml:

VS CodeRustPython

Relation chain

.tomlextension of

format

tomlserved as

mime type

application/tomlsent via header

http header

Related extensions

Related MIME types

Related programming languages

TOML

.toml .toml.example

Common uses

Configuration files
Data interchange between systems
API request and response payloads
Logs and data exports

How to edit .toml files

Open the file with VS Code, make your changes and save.
Most editors preserve the original formatting and encoding — avoid changing the charset.

How to create .toml files

Create a new file and save it with the .toml extension, or export this format from VS Code.

Example

name = "refnet"
version = "1.0.0"

[server]
port = 3001

Frequently asked questions

What programs can open .toml files?

Common options include VS Code, Rust, Python. You can also open many of these files with built-in viewers or a browser.

How do I create a .toml file?

Create a new file in any text editor or the app that owns the format and save it with the .toml extension.

What is the relationship between .toml and the application/toml MIME type?

application/toml is the media type identifier used for .toml files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-09-13

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