diff --git a/CHANGES.md b/CHANGES.md
index 92f6d7b2f5..82d853a84e 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -15,6 +15,7 @@ These changes should be for the better and should not be super noticeable but if
 
 Grammars:
 
+- enh(arcade) updated to ArcGIS Arcade version 1.16 [John Foster][]
 - enh(php) Left and right-side of double colon [Wojciech Kania][]
 - enh(php) add PHP constants [Wojciech Kania][]
 - enh(php) add PHP 8.1 keywords [Wojciech Kania][]
@@ -57,6 +58,7 @@ Themes:
 
 - Modified background color in css for Gradient Light and Gradient Dark themes [Samia Ali][]
 
+[John Foster]: https://github.com/jf990
 [Pegasis]: https://github.com/PegasisForever
 [Wojciech Kania]: https://github.com/wkania
 [Jeylani B]: https://github.com/jeyllani
diff --git a/src/languages/arcade.js b/src/languages/arcade.js
index 579d5b475a..6de745189d 100644
--- a/src/languages/arcade.js
+++ b/src/languages/arcade.js
@@ -42,14 +42,18 @@ export default function(hljs) {
     built_in: [
       "Abs",
       "Acos",
+      "All",
       "Angle",
-      "Attachments",
+      "Any",
       "Area",
       "AreaGeodetic",
+      "Array",
       "Asin",
       "Atan",
       "Atan2",
+      "Attachments",
       "Average",
+      "Back",
       "Bearing",
       "Boolean",
       "Buffer",
@@ -57,9 +61,11 @@ export default function(hljs) {
       "Ceil",
       "Centroid",
       "Clip",
+      "Concatenate",
       "Console",
       "Constrain",
       "Contains",
+      "ConvertDirection",
       "Cos",
       "Count",
       "Crosses",
@@ -70,45 +76,71 @@ export default function(hljs) {
       "Day",
       "Decode",
       "DefaultValue",
+      "Densify",
+      "DensifyGeodetic",
       "Dictionary",
       "Difference",
       "Disjoint",
       "Distance",
       "DistanceGeodetic",
       "Distinct",
+      "Domain",
       "DomainCode",
       "DomainName",
+      "EnvelopeIntersects",
       "Equals",
+      "Erase",
       "Exp",
+      "Expects",
       "Extent",
       "Feature",
       "FeatureSet",
       "FeatureSetByAssociation",
       "FeatureSetById",
+      "FeatureSetByName",
       "FeatureSetByPortalItem",
       "FeatureSetByRelationshipName",
-      "FeatureSetByTitle",
-      "FeatureSetByUrl",
       "Filter",
+      "Find",
       "First",
       "Floor",
+      "FromCharCode",
+      "FromCodePoint",
+      "FromJSON",
+      "GdbVersion",
+      "Generalize",
       "Geometry",
+      "GetFeatureSet",
+      "GetUser",
       "GroupBy",
       "Guid",
+      "Hash",
       "HasKey",
       "Hour",
       "IIf",
+      "Includes",
       "IndexOf",
+      "Insert",
       "Intersection",
       "Intersects",
       "IsEmpty",
       "IsNan",
+      "ISOMonth",
+      "ISOWeek",
+      "ISOWeekday",
+      "ISOYear",
       "IsSelfIntersecting",
+      "IsSimple",
+      "Left|0",
       "Length",
+      "Length3D",
       "LengthGeodetic",
       "Log",
+      "Lower",
+      "Map",
       "Max",
       "Mean",
+      "Mid",
       "Millisecond",
       "Min",
       "Minute",
@@ -116,45 +148,80 @@ export default function(hljs) {
       "MultiPartToSinglePart",
       "Multipoint",
       "NextSequenceValue",
+      "None",
       "Now",
       "Number",
+      "Offset|0",
       "OrderBy",
       "Overlaps",
       "Point",
       "Polygon",
       "Polyline",
+      "Pop",
       "Portal",
       "Pow",
+      "Proper",
+      "Push",
       "Random",
+      "Reduce",
       "Relate",
+      "Replace",
+      "Resize",
       "Reverse",
-      "RingIsClockWise",
+      "Right|0",
+      "RingIsClockwise",
+      "Rotate",
       "Round",
+      "Schema",
       "Second",
       "SetGeometry",
+      "Simplify",
       "Sin",
+      "Slice",
       "Sort",
+      "Splice",
+      "Split",
       "Sqrt",
       "Stdev",
+      "SubtypeCode",
+      "SubtypeName",
+      "Subtypes",
       "Sum",
       "SymmetricDifference",
       "Tan",
       "Text",
       "Timestamp",
+      "ToCharCode",
+      "ToCodePoint",
       "Today",
+      "ToHex",
       "ToLocal",
-      "Top",
+      "Top|0",
       "Touches",
       "ToUTC",
+      "TrackAccelerationAt",
+      "TrackAccelerationWindow",
+      "TrackCurrentAcceleration",
+      "TrackCurrentDistance",
+      "TrackCurrentSpeed",
       "TrackCurrentTime",
+      "TrackDistanceAt",
+      "TrackDistanceWindow",
+      "TrackDuration",
+      "TrackFieldWindow",
       "TrackGeometryWindow",
       "TrackIndex",
+      "TrackSpeedAt",
+      "TrackSpeedWindow",
       "TrackStartTime",
       "TrackWindow",
+      "Trim",
       "TypeOf",
       "Union",
+      "Upper",
       "UrlEncode",
       "Variance",
+      "Week",
       "Weekday",
       "When",
       "Within",
@@ -204,6 +271,7 @@ export default function(hljs) {
 
   return {
     name: 'ArcGIS Arcade',
+    case_insensitive: true,
     keywords: KEYWORDS,
     contains: [
       hljs.APOS_STRING_MODE,
diff --git a/test/markup/arcade/profile.expect.txt b/test/markup/arcade/profile.expect.txt
index d4a9dce5f2..f30c09e4b6 100644
--- a/test/markup/arcade/profile.expect.txt
+++ b/test/markup/arcade/profile.expect.txt
@@ -3,7 +3,7 @@
 */</span>
 <span class="hljs-keyword">function</span> <span class="hljs-title function_">offsetPopulation</span>(<span class="hljs-params">offset</span>){
    <span class="hljs-keyword">var</span> popDensity = <span class="hljs-built_in">Round</span>( <span class="hljs-symbol">$feature</span>.POPULATION / <span class="hljs-built_in">AreaGeodetic</span>(<span class="hljs-built_in">Geometry</span>(<span class="hljs-symbol">$feature</span>), <span class="hljs-string">&quot;square-kilometers&quot;</span>) );
-   <span class="hljs-keyword">var</span> geom = <span class="hljs-built_in">Geometry</span>({ <span class="hljs-string">&#x27;x&#x27;</span>: offset.x, <span class="hljs-string">&#x27;y&#x27;</span>: offset.y, <span class="hljs-string">&#x27;spatialReference&#x27;</span>:{<span class="hljs-string">&#x27;wkid&#x27;</span>:<span class="hljs-number">102100</span>} });
+   <span class="hljs-keyword">var</span> geom = <span class="hljs-built_in">Geometry</span>({ <span class="hljs-string">&#x27;x&#x27;</span>: <span class="hljs-built_in">offset</span>.x, <span class="hljs-string">&#x27;y&#x27;</span>: <span class="hljs-built_in">offset</span>.y, <span class="hljs-string">&#x27;spatialReference&#x27;</span>:{<span class="hljs-string">&#x27;wkid&#x27;</span>:<span class="hljs-number">102100</span>} });
    <span class="hljs-keyword">var</span> myLayer = <span class="hljs-built_in">FeatureSet</span>(<span class="hljs-symbol">$map</span>, [<span class="hljs-string">&quot;POPULATION&quot;</span>, <span class="hljs-string">&quot;ELECTION-DATA&quot;</span>]);
    <span class="hljs-keyword">return</span> popDensity;
 }