# How to enable source maps
Source mapping is a technique that "maps" your browser inspector's line numbers to the source file. This is useful when working with assets that are compiled from LESS, SASS, Coffeescript and so on. Source maps can also be used with minified assets that would normally have their line numbers removed. If you're curious, [here's some more information regarding source maps](http://blog.teamtreehouse.com/introduction-source-maps).
## Chrome
1. Open Developer Tools.
- Mac users: **View > Developer > Developer Tools**.
2. Click the Settings cog icon in the upper-right corner of the Developer Tools window.
3. Under the **Sources** section, check the box(es) for the source maps you want to enable.
## Firefox
1. Open the Developer Tools.
- Mac users: **Tools > Web Developer > Toggle Tools**
2. Click the Settings cog icon in the upper-left corner of the Developer Tools window.
3. Under the **Style Editor** section, check the box for **Show original sources**.
## Safari
Source-mapping is enabled by default.
## Internet Explorer
Source-mapping is enabled by default in IE 11 with the Windows 8.1 update installed. No other versions of IE support source-mapping. [Here's some more information from MSDN regarding IE11 and source maps](http://msdn.microsoft.com/en-US/library/ie/dn255007%28v=vs.85%29#source_maps).