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

Quick facts

Extension.xsl

File typeXSL Stylesheet

MIME typeapplication/xml

CategoryData & Text

Charset—

CompressibleYes

Format familyxml

What is .xsl

What is a .xsl file?

A .xsl file is a XSL Stylesheet — XSL Transformations stylesheet for converting XML.

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

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

How to open .xsl files

Use VS Code or Saxon to open and edit .xsl 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/xml

Common software that reads/writes .xsl:

VS CodeSaxon

Relation chain

.xslextension of

format

xmlserved as

mime type

application/xmlsent via header

http header

Related extensions

Related MIME types

Related programming languages

XSLT

.xslt .xsl

Common uses

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

How to edit .xsl 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 .xsl files

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

Frequently asked questions

What programs can open .xsl files?

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

How do I create a .xsl file?

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

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

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

Sources & standards

Updated 2026-08-18

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