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.JSONML·File Extension

JSONML Data & Text — A .jsonml file is a JSONML Data & Text. It is a text-based data format widely used for configuration files, data interchange and API payloads.

Data & Textapplication/jsonml+jsonCompressible

Quick facts

Extension.jsonml

File typeJSONML Data & Text

MIME typeapplication/jsonml+json

CategoryData & Text

Charset—

CompressibleYes

What is .jsonml

What is a .jsonml file?

A .jsonml file is a JSONML Data & Text. It is a text-based data format widely used for configuration files, data interchange and API payloads.

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

Related entities: it maps to application/jsonml+json — and is delivered over HTTP via the Content-Type header.

How to open .jsonml files

Use VS Code or Notepad++ to open and edit .jsonml 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/jsonml+json

Common software that reads/writes .jsonml:

VS CodeNotepad++Sublime Textjq

Relation chain

.jsonmlextension of

format

JSONML Data & Textserved as

mime type

application/jsonml+jsonsent via header

http header

Related extensions

Related MIME types

application/jsonml+json

.jsonml

Common uses

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

How to edit .jsonml 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 .jsonml files

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

Frequently asked questions

What programs can open .jsonml files?

Common options include VS Code, Notepad++, Sublime Text. You can also open many of these files with built-in viewers or a browser.

How do I create a .jsonml file?

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

What is the relationship between .jsonml and the application/jsonml+json MIME type?

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

Sources & standards

Updated 2026-09-13

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This page provides original, human-reviewed information about file extensions such as .jsonml, the File Extension Reference and related concepts. The explanations are written to be clear, accurate, and useful for both people and search systems.

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