WebKit Environment variables

This page documents some environment variables that you can use to change the behaviour of WebKit.

This documentation may be outdated or incomplete. If you wish, you can grep the sourcecode for getenv strings and update this document.

List of WebKit environment variables

• Use the following environment variables as:

  export Variable="Value"
  $WebKitCommand
  

Variable	Value	Meaning	WebKit ports
JavaScriptCoreUseJIT	0	Disable the JavaScript JIT	ALL
JSC_useFTLJIT	0	Disable the JavaScript FTL JIT	ALL
JSC_dumpOptions	3	Dumps all the JSC options available to tweak	ALL
JSC_${option from previous command}	${value}	${check with JSC_dumpOptions=3}	ALL
Malloc	1	Disable bmalloc memory allocator and use the system default one instead	ALL
USE_NATIVE_XDISPLAY	1	Run the WebKit layout or performance tests on the current X server instead inside Xvfb	GTK+/EFL
WEBKITGTK_EXPERIMENTAL_FEATURES	REGION_BASED_COLUMNS=1	Enable region based columns (implement multicol using the CSS regions implementation rather than ColumnInfo & co)	GTK+
WEBKIT_FORCE_COMPOSITING_MODE	Anything	Force Accelerated Compositing mode to be always on	GTK+ (since r193626)