diff --git a/devtools/shared/css/generated/properties-db.js b/devtools/shared/css/generated/properties-db.js
index fd8635bbfa..587f5704d1 100644
--- a/devtools/shared/css/generated/properties-db.js
+++ b/devtools/shared/css/generated/properties-db.js
@@ -2208,10 +2208,10 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
       "content",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -2231,10 +2231,10 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
       "content",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -3282,7 +3282,6 @@ exports.CSS_PROPERTIES = {
       "-moz-crisp-edges",
       "-moz-deck",
       "-moz-element",
-      "-moz-fit-content",
       "-moz-grid",
       "-moz-grid-group",
       "-moz-grid-line",
@@ -3424,6 +3423,7 @@ exports.CSS_PROPERTIES = {
       "extra-expanded",
       "fill",
       "fill-box",
+      "fit-content",
       "fixed",
       "flat",
       "flex",
@@ -6000,10 +6000,10 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
       "content",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -6023,10 +6023,10 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
       "content",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -6816,9 +6816,9 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -6903,9 +6903,9 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -7782,8 +7782,8 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -7804,8 +7804,8 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -7826,8 +7826,8 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -7866,9 +7866,9 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -7888,9 +7888,9 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -7910,9 +7910,9 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
@@ -9710,9 +9710,9 @@ exports.CSS_PROPERTIES = {
     "values": [
       "-moz-available",
       "-moz-calc",
-      "-moz-fit-content",
       "auto",
       "calc",
+      "fit-content",
       "inherit",
       "initial",
       "max-content",
diff --git a/layout/base/nsLayoutUtils.cpp b/layout/base/nsLayoutUtils.cpp
index e156e432d3..fb7390753d 100644
--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -4726,8 +4726,8 @@ GetDefiniteSizeTakenByBoxSizing(StyleBoxSizing aBoxSizing,
 }
 
 // Handles only max-content and min-content, and
-// -moz-fit-content for min-width and max-width, since the others
-// (-moz-fit-content for width, and -moz-available) have no effect on
+// fit-content for min-width and max-width, since the others
+// (fit-content for width, and -moz-available) have no effect on
 // intrinsic widths.
 enum eWidthProperty { PROP_WIDTH, PROP_MAX_WIDTH, PROP_MIN_WIDTH };
 static bool
@@ -5038,7 +5038,7 @@ nsLayoutUtils::IntrinsicForAxis(PhysicalAxis              aAxis,
   if (styleISize.GetUnit() == eStyleUnit_Enumerated &&
       (styleISize.GetIntValue() == NS_STYLE_WIDTH_MAX_CONTENT ||
        styleISize.GetIntValue() == NS_STYLE_WIDTH_MIN_CONTENT)) {
-    // -moz-fit-content and -moz-available enumerated widths compute intrinsic
+    // fit-content and -moz-available enumerated widths compute intrinsic
     // widths just like auto.
     // For max-content and min-content, we handle them like
     // specified widths, but ignore box-sizing.
@@ -5054,7 +5054,7 @@ nsLayoutUtils::IntrinsicForAxis(PhysicalAxis              aAxis,
     ++gNoiseIndent;
 #endif
     if (aType != MIN_ISIZE) {
-      // At this point, |styleISize| is auto/-moz-fit-content/-moz-available or
+      // At this point, |styleISize| is auto/fit-content/-moz-available or
       // has a percentage.  The intrinisic size for those under a max-content
       // constraint is the max-content contribution which we shouldn't clamp.
       aMarginBoxMinSizeClamp = NS_MAXSIZE;
diff --git a/layout/style/nsCSSKeywordList.h b/layout/style/nsCSSKeywordList.h
index bbe25893dd..033ca5db17 100644
--- a/layout/style/nsCSSKeywordList.h
+++ b/layout/style/nsCSSKeywordList.h
@@ -63,7 +63,6 @@ CSS_KEY(-moz-element, _moz_element)
 CSS_KEY(-moz-eventreerow, _moz_eventreerow)
 CSS_KEY(-moz-field, _moz_field)
 CSS_KEY(-moz-fieldtext, _moz_fieldtext)
-CSS_KEY(-moz-fit-content, _moz_fit_content)
 CSS_KEY(-moz-fixed, _moz_fixed)
 CSS_KEY(-moz-grabbing, _moz_grabbing)
 CSS_KEY(-moz-grab, _moz_grab)
diff --git a/layout/style/nsCSSProps.cpp b/layout/style/nsCSSProps.cpp
index 7f1fe2c18f..9acc69daf1 100644
--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -2260,7 +2260,7 @@ const KTableEntry nsCSSProps::kWhitespaceKTable[] = {
 const KTableEntry nsCSSProps::kWidthKTable[] = {
   { eCSSKeyword_max_content, NS_STYLE_WIDTH_MAX_CONTENT },
   { eCSSKeyword_min_content, NS_STYLE_WIDTH_MIN_CONTENT },
-  { eCSSKeyword__moz_fit_content, NS_STYLE_WIDTH_FIT_CONTENT },
+  { eCSSKeyword_fit_content, NS_STYLE_WIDTH_FIT_CONTENT },
   { eCSSKeyword__moz_available, NS_STYLE_WIDTH_AVAILABLE },
   { eCSSKeyword_UNKNOWN, -1 }
 };
@@ -2269,7 +2269,7 @@ const KTableEntry nsCSSProps::kWidthKTable[] = {
 const KTableEntry nsCSSProps::kFlexBasisKTable[] = {
   { eCSSKeyword_max_content, NS_STYLE_WIDTH_MAX_CONTENT },
   { eCSSKeyword_min_content, NS_STYLE_WIDTH_MIN_CONTENT },
-  { eCSSKeyword__moz_fit_content, NS_STYLE_WIDTH_FIT_CONTENT },
+  { eCSSKeyword_fit_content, NS_STYLE_WIDTH_FIT_CONTENT },
   { eCSSKeyword__moz_available, NS_STYLE_WIDTH_AVAILABLE },
   { eCSSKeyword_content, NS_STYLE_FLEX_BASIS_CONTENT },
   { eCSSKeyword_UNKNOWN, -1 }
diff --git a/layout/style/res/forms.css b/layout/style/res/forms.css
index fcf5874829..6d0a5503ae 100644
--- a/layout/style/res/forms.css
+++ b/layout/style/res/forms.css
@@ -55,7 +55,7 @@
 fieldset > legend {
   padding-inline-start: 2px;
   padding-inline-end: 2px;
-  inline-size: -moz-fit-content;
+  inline-size: fit-content;
 }
 
 legend {
diff --git a/layout/style/res/html.css b/layout/style/res/html.css
index 7f792a06bc..38814a8354 100644
--- a/layout/style/res/html.css
+++ b/layout/style/res/html.css
@@ -820,7 +820,7 @@ dialog {
   padding: 1em;
   color: #222; /*CanvasText*/
   background: snow; /*Canvas*/
-  width: -moz-fit-content;
+  width: fit-content;
 }
 
 dialog:not([open]) {
diff --git a/layout/tables/BasicTableLayoutStrategy.cpp b/layout/tables/BasicTableLayoutStrategy.cpp
index 8ece42fcb3..c599142252 100644
--- a/layout/tables/BasicTableLayoutStrategy.cpp
+++ b/layout/tables/BasicTableLayoutStrategy.cpp
@@ -179,7 +179,7 @@ GetISizeInfo(nsRenderingContext *aRenderingContext,
         if (!aIsCell || maxISize.GetIntValue() == NS_STYLE_WIDTH_AVAILABLE) {
             maxISize.SetNoneValue();
         } else if (maxISize.GetIntValue() == NS_STYLE_WIDTH_FIT_CONTENT) {
-            // for 'max-inline-size', '-moz-fit-content' is like
+            // for 'max-inline-size', 'fit-content' is like
             // 'max-content'
             maxISize.SetIntValue(NS_STYLE_WIDTH_MAX_CONTENT,
                                  eStyleUnit_Enumerated);
@@ -206,7 +206,7 @@ GetISizeInfo(nsRenderingContext *aRenderingContext,
         if (!aIsCell || minISize.GetIntValue() == NS_STYLE_WIDTH_AVAILABLE) {
             minISize.SetCoordValue(0);
         } else if (minISize.GetIntValue() == NS_STYLE_WIDTH_FIT_CONTENT) {
-            // for 'min-inline-size', '-moz-fit-content' is like
+            // for 'min-inline-size', 'fit-content' is like
             // 'min-content'
             minISize.SetIntValue(NS_STYLE_WIDTH_MIN_CONTENT,
                                  eStyleUnit_Enumerated);
diff --git a/layout/tables/FixedTableLayoutStrategy.cpp b/layout/tables/FixedTableLayoutStrategy.cpp
index 072be701a8..d1b30b9059 100644
--- a/layout/tables/FixedTableLayoutStrategy.cpp
+++ b/layout/tables/FixedTableLayoutStrategy.cpp
@@ -111,7 +111,7 @@ FixedTableLayoutStrategy::GetMinISize(nsRenderingContext* aRenderingContext)
             result -= spacing * (colSpan - 1);
           }
         }
-        // else, for 'auto', '-moz-available', '-moz-fit-content',
+        // else, for 'auto', '-moz-available', 'fit-content',
         // and 'calc()' with percentages, do nothing
       }
     }
@@ -266,7 +266,7 @@ FixedTableLayoutStrategy::ComputeColumnISizes(const ReflowInput& aReflowInput)
           colFrame->AddPrefPercent(pct);
           pctTotal += pct;
         } else {
-          // 'auto', '-moz-available', '-moz-fit-content', and 'calc()'
+          // 'auto', '-moz-available', 'fit-content', and 'calc()'
           // with percentages
           colISize = unassignedMarker;
         }