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.CIF·File Extension

CIF Other — A .cif file is a CIF Other. It is a file format typically read and written by specialized applications.

Otherchemical/x-cif

Quick facts

Extension.cif
File typeCIF Other
MIME typechemical/x-cif
CategoryOther
Charset—
Compressible—

What is .cif

What is a .cif file?

A .cif file is a CIF Other. It is a file format typically read and written by specialized applications.

In the mime-db registry it maps to chemical/x-cif. When serving .cif over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to chemical/x-cif — and is delivered over HTTP via the Content-Type header.

How to open .cif files

  • Use VS Code or xxd to open and edit .cif 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: chemical/x-cif

Common software that reads/writes .cif:

VS Codexxd7-Zip

Relation chain

.cifextension of
format
CIF Otherserved as
mime type
chemical/x-cifsent via header
http header
Content-Type

Related extensions

.cdx
CDX Other
.cmdf
CMDF Other
.cml
CML Other
.csml
CSML Other

Related MIME types

chemical/x-cif
.cif

Common uses

  • Application-specific data

How to edit .cif 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 .cif files

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

Frequently asked questions

What programs can open .cif files?

Common options include VS Code, xxd, 7-Zip. You can also open many of these files with built-in viewers or a browser.

How do I create a .cif file?

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

What is the relationship between .cif and the chemical/x-cif MIME type?

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

Sources & standards

Updated 2026-09-13

Explore this reference

Related extensions

.cdx
CDX Other
.cmdf
CMDF Other
.cml
CML Other
.csml
CSML Other

Related MIME types

chemical/x-cif
.cif

Related headers

Content-Type
HTTP header
Accept
HTTP header

Related methods

GET
HTTP method
POST
HTTP method
PUT
HTTP method
PATCH
HTTP method

Related status codes

200
OK
404
Not Found

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