lookup> .z3

.Z3·File Extension

Z3 Data & Text — A .z3 file is a Z3 Data & Text. It is a text-based data format widely used for configuration files, data interchange and API payloads.

Data & Textapplication/x-zmachine

Quick facts

Extension.z3

File typeZ3 Data & Text

MIME typeapplication/x-zmachine

CategoryData & Text

Charset—

Compressible—

What is .z3

What is a .z3 file?

A .z3 file is a Z3 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/x-zmachine. When serving .z3 over HTTP, set the Content-Type header as shown in Developer info below.

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

How to open .z3 files

Use VS Code or Notepad++ to open and edit .z3 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/x-zmachine

Common software that reads/writes .z3:

VS CodeNotepad++Sublime Textjq

Relation chain

.z3extension of

format

Z3 Data & Textserved as

mime type

application/x-zmachinesent via header

http header

Related extensions

Related MIME types

application/x-zmachine

.z1 .z2 .z3

Related programming languages

SMT

.smt2 .smt .z3

Common uses

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

How to edit .z3 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 .z3 files

Create a new file and save it with the .z3 extension, or export this format from VS Code.

Frequently asked questions

What programs can open .z3 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 .z3 file?

Create a new file in any text editor or the app that owns the format and save it with the .z3 extension.

What is the relationship between .z3 and the application/x-zmachine MIME type?

application/x-zmachine is the media type identifier used for .z3 files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-08-18

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