lookup> .cxx

.CXX·File Extension

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

Data & Texttext/x-c

Quick facts

Extension.cxx

File typeCXX Data & Text

MIME typetext/x-c

CategoryData & Text

Charset—

Compressible—

What is .cxx

What is a .cxx file?

A .cxx file is a CXX 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 text/x-c. When serving .cxx over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to text/x-c and is used by C++ among others — and is delivered over HTTP via the Content-Type header.

How to open .cxx files

Use VS Code or Notepad++ to open and edit .cxx 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: text/x-c

Common software that reads/writes .cxx:

VS CodeNotepad++Sublime Textjq

Relation chain

.cxxextension of

format

CXX Data & Textserved as

mime type

text/x-csent via header

http header

Related extensions

Related MIME types

Related programming languages

C++

.cpp .c++ .cc

Common uses

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

How to edit .cxx 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 .cxx files

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

Frequently asked questions

What programs can open .cxx 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 .cxx file?

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

What is the relationship between .cxx and the text/x-c MIME type?

text/x-c is the media type identifier used for .cxx files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-08-18

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