A vendor prefix is used to indicate that a feature is specific to a certain browser. Firefox supports several extensions to CSS, which are prefixed with -moz-.
Note: These extensions are mostly experimental or deprecated but kept for backward compatibility. You should avoid using them on production websites.
-moz-float-edge -moz-force-broken-image-icon : Use alt text instead.-moz-orient-moz-osx-font-smoothing: A similar font-smooth equivalent exists.-moz-user-focus -moz-user-input -moz-user-modify: A non-prefixed user-modify equivalent exists, but the HTML contenteditable attribute is recommended instead.The following properties were implemented first using the -moz- vendor prefix, but are now supported in Firefox using the standard (non-prefixed) syntax. Support for the prefixed version is typically dropped eventually, so use the standard property instead.
-moz-animation : Prefixed version still supported.-moz-animation-delay : Prefixed version still supported.-moz-animation-direction : Prefixed version still supported.-moz-animation-duration : Prefixed version still supported.-moz-animation-fill-mode : Prefixed version still supported.-moz-animation-iteration-count : Prefixed version still supported.-moz-animation-name : Prefixed version still supported.-moz-animation-play-state : Prefixed version still supported.-moz-animation-timing-function : Prefixed version still supported.-moz-appearance: The prefixed version of appearance is still supported.-moz-backface-visibility : Prefixed version still supported.-moz-background-clip : Not supported; use background-clip.-moz-background-origin : Not supported; use background-origin.-moz-box-align : Use CSS flexbox with align-items.-moz-background-inline-policy : Not supported; use box-decoration-break.-moz-box-direction : Use CSS flexbox with flex-direction.-moz-box-flex : Use CSS flexbox with flex-grow.-moz-box-ordinal-group : Use CSS flexbox with order.-moz-box-orient : Use CSS flexbox with flex-direction.-moz-box-pack : Use CSS flexbox with justify-content.-moz-background-size : Not supported; use background-size.-moz-border-end : Not supported; use border-inline-end.-moz-border-end-color : Not supported; use border-inline-end-color.-moz-border-end-style : Not supported; use border-inline-end-style.-moz-border-end-width : Not supported; use border-inline-end-width.-moz-border-image : Not supported; use border-inline-end-width.-moz-border-start : Not supported; use border-inline-start.-moz-border-start-color : Not supported; use border-inline-start-color.-moz-border-start-style : Not supported; use border-inline-start-style.-moz-border-start-width : Not supported; use border-inline-start-width.-moz-box-sizing : Prefixed version still supported.-moz-column-count : Not supported; use column-count.-moz-column-fill : Not supported; use column-fill.-moz-column-gap : Not supported; use column-gap.-moz-column-width : Not supported; use column-width.-moz-column-rule : Not supported; use column-rule.-moz-column-rule-width : Not supported; use column-rule-width.-moz-column-rule-style : Not supported; use column-rule-style.-moz-column-rule-color : Not supported; use column-rule-color.-moz-font-feature-settings : Prefixed version still supported.-moz-font-language-override : Prefixed version still supported.-moz-hyphens : Prefixed version still supported.-moz-margin-end : Not supported; use margin-inline-end.-moz-margin-start : Not supported; use margin-inline-start.-moz-opacity : Not supported; use opacity.-moz-outline : Not supported; use outline.-moz-outline-color : Not supported; use outline-color.-moz-outline-offset : Not supported; use outline-offset.-moz-outline-style : Not supported; use outline-style.-moz-outline-width : Not supported; use outline-width.-moz-padding-end : Not supported; use padding-inline-end.-moz-padding-start : Not supported; use padding-inline-start.-moz-perspective : Prefixed version still supported.-moz-perspective-origin : Prefixed version still supported.-moz-tab-size: Use tab-size-moz-text-align-last : Not supported; use text-align-last.-moz-text-decoration-color : Not supported; use text-decoration-color.-moz-text-decoration-line : Not supported; use text-decoration-line.-moz-text-decoration-style : Not supported; use text-decoration-style.-moz-text-size-adjust: See text-size-adjust .-moz-transform : Prefixed version still supported.-moz-transform-origin : Prefixed version still supported.-moz-transform-style : Prefixed version still supported.-moz-transition : Not supported; use transition.-moz-transition-delay : Not supported; use transition-delay.-moz-transition-duration : Not supported; use transition-duration.-moz-transition-property : Not supported; use transition-property.-moz-transition-timing-function : Not supported; use transition-timing-function.-moz-user-select: Use user-select.-moz-initial: See initial.Property: background-image
-moz-linear-gradient : Use linear-gradient().-moz-radial-gradient : Use radial-gradient().-moz-element : Use element().-moz-image-rect() Properties: border-style and outline-style.
-moz-bg-inset -moz-bg-outset -moz-bg-solid Type: <color>
-moz-activehyperlinktext-moz-hyperlinktext-moz-visitedhyperlinktext-moz-buttonhoverface-moz-buttonhovertext-moz-default-background-color-moz-default-color-moz-cellhighlight-moz-cellhighlighttext-moz-field-moz-fieldtext-moz-dialog-moz-dialogtext-moz-menuhover-moz-menuhovertextProperty: empty-cells
-moz-show-background (default value in quirks mode)Property: font-family
-moz-fixedProperty: image-rendering
-moz-crisp-edges : Use crisp-edges.Type: <length>
-moz-calc: Use calc().Property: list-style-type
Several vendor-prefixed values for list-style-type are now supported as standard values without a -moz- prefix, except for those in the following list. See Browser Compatibility for details.
-moz-ethiopic-halehame-moz-ethiopic-halehame-am-moz-ethiopic-halehame-ti-er-moz-ethiopic-halehame-ti-et-moz-hangul-moz-hangul-consonant-moz-urduProperty: text-align
-moz-center : Use text-align: center.-moz-left : Use text-align: left.-moz-right : Use text-align: right.Properties: width, min-width, and max-width
-moz-min-content: See min-content.-moz-fit-content: See fit-content.-moz-max-content: See max-content.-moz-available: See stretch.:-moz-any : Use :is.:-moz-any-link : Use :any-link.:-moz-broken :-moz-drag-over:-moz-first-node:-moz-full-screen : Not supported; use :fullscreen.:-moz-full-screen-ancestor : Not supported; use :fullscreen.:-moz-handler-blocked:-moz-handler-crashed:-moz-handler-disabled:-moz-last-node:-moz-loading:-moz-locale-dir(ltr):-moz-locale-dir(rtl):-moz-native-anonymous:-moz-placeholder : Use :placeholder-shown.:-moz-only-whitespace:-moz-read-only : Use :read-only.:-moz-read-write : Use :read-write.:-moz-submit-invalid: See :invalid.:-moz-suppressed:-moz-ui-invalid : Use :user-invalid.:-moz-ui-valid : Use :user-valid.:-moz-user-disabled:-moz-window-inactive::-moz-canvas::-moz-cell-content::-moz-color-swatch::-moz-focus-inner::-moz-focus-outer::-moz-inline-table::-moz-list-bullet::-moz-list-number::-moz-meter-bar::-moz-pagebreak::-moz-pagecontent::-moz-placeholder : Use ::placeholder.::-moz-progress-bar::-moz-range-progress::-moz-range-thumb::-moz-range-track::-moz-scrolled-canvas::-moz-scrolled-content::-moz-selection : Use ::selection.::-moz-svg-foreign-content::-moz-table::-moz-table-cell::-moz-table-column::-moz-table-column-group::-moz-table-outer::-moz-table-row::-moz-table-row-group::-moz-viewport::-moz-viewport-scroll-moz-device-pixel-ratio -moz-platform-moz-windows-glass-moz-alt-content: See Firefox bug 11011