LESS Data & Text — A .less file is a LESS Data & Text. It is a text-based data format widely used for configuration files, data interchange and API payloads.
Quick facts
What is .less
A .less file is a LESS 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/less, and it is marked as compressible. When serving .less over HTTP, set the Content-Type header as shown in Developer info below.
Related entities: it maps to text/less and is used by Less among others — and is delivered over HTTP via the Content-Type header.
How to open .less files
Developer info
When served over HTTP, responses should set the following header:
Content-Type: text/less
Common software that reads/writes .less:
Relation chain
Related extensions
Related MIME types
Related programming languages
Common uses
How to edit .less files
How to create .less files
Frequently asked questions
Common options include VS Code, Notepad++, Sublime Text. You can also open many of these files with built-in viewers or a browser.
Create a new file in any text editor or the app that owns the format and save it with the .less extension.
text/less is the media type identifier used for .less files during network transfer (for example in the HTTP Content-Type header).
Sources & standards
Updated 2026-08-18
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