Most of non-standard CSS display values have been dropped

Published: | Categories: CSS


The non-standard, -moz-prefixed CSS display property values, originally intended for Mozilla application UI, are no longer available from web content. The standard Flexible Box Layout or Grid Layout should be used instead.

  • -moz-deck
  • -moz-grid
  • -moz-grid-group
  • -moz-grid-line
  • -moz-groupbox
  • -moz-inline-grid
  • -moz-inline-stack
  • -moz-popup
  • -moz-stack

For the meantime, the following values will be left due to concerns over compatibility issues. Firefox developers are planning to use Telemetry to understand the usage on the web before removing these exceptions.

  • -moz-box
  • -moz-inline-box

Update: -moz-box and -moz-inline-box are also deprecated as of Firefox 63.

Update 2: -moz-box and -moz-inline-box have been removed with Firefox 64.