diff --git a/website/utils/test/url_utils.test.ts b/website/utils/test/url_utils.test.ts
index adc8f823..2b588000 100644
--- a/website/utils/test/url_utils.test.ts
+++ b/website/utils/test/url_utils.test.ts
@@ -489,16 +489,15 @@ describe("Viewer state", () => {
       expect(serializeViewerState(CUSTOM_VIEWER_STATE, false)).toEqual(SERIALIZED_CUSTOM_VIEWER_STATE);
     });
 
-    it("deserializes partial camera settings", () => {
-      const state: Partial<ViewerState> = {
-        cameraState: {
-          position: [1.0, -1.4, 45],
-          up: [0, 1, 0],
-          fov: 43.5,
-        },
+    it("shortens long numbers in the slice and region parameters", () => {
+      // Floats should be rounded to 5 significant digits or less
+      let state: Partial<ViewerState> = {
+        region: { x: [0.4566666666, 0.8667332], y: [0.49999999, 0.8999999], z: [0.3000000001, 0.16467883] },
+        slice: { x: 0.41111186, y: 0.49999999, z: 0.677402 },
       };
-      const serializedState = "pos:1:-1.4:45,up:0:1:0,fov:43.5";
-      expect(deserializeViewerState({ cam: serializedState })).toEqual(state);
+      let serializedState = serializeViewerState(state, true);
+      expect(serializedState.reg).toEqual("0.45667:0.86673,0.5:0.9,0.3:0.16468");
+      expect(serializedState.slice).toEqual("0.41111,0.5,0.6774");
     });
   });
 
@@ -532,6 +531,18 @@ describe("Viewer state", () => {
         expect(deserializeViewerState(serializeViewerState(state, false)).renderMode).toEqual(renderMode);
       }
     });
+
+    it("deserializes partial camera settings", () => {
+      const state: Partial<ViewerState> = {
+        cameraState: {
+          position: [1.0, -1.4, 45],
+          up: [0, 1, 0],
+          fov: 43.5,
+        },
+      };
+      const serializedState = "pos:1:-1.4:45,up:0:1:0,fov:43.5";
+      expect(deserializeViewerState({ cam: serializedState })).toEqual(state);
+    });
   });
 });
 
diff --git a/website/utils/url_utils.ts b/website/utils/url_utils.ts
index ff908bbc..c2d55226 100644
--- a/website/utils/url_utils.ts
+++ b/website/utils/url_utils.ts
@@ -554,6 +554,24 @@ function formatFloat(value: number, maxPrecision: number = 5): string {
   return Number(value.toPrecision(maxPrecision)).toString();
 }
 
+function perAxisToArray<T>(perAxis: PerAxis<T>): T[] {
+  return [perAxis.x, perAxis.y, perAxis.z];
+}
+
+/** Serializes a region into a `x1:x2,y1:y2,z1:z2` string format. */
+function serializeRegion(region: PerAxis<[number, number]>): string {
+  return perAxisToArray(region)
+    .map((axis) => axis.map((val) => formatFloat(val)).join(":"))
+    .join(",");
+}
+
+/** Serializes a slice parameter into a `x,y,z` string format. */
+function serializeSlice(slice: PerAxis<number>): string {
+  return perAxisToArray(slice)
+    .map((val) => formatFloat(val))
+    .join(",");
+}
+
 function serializeBoolean(value: boolean | undefined): "1" | "0" | undefined {
   if (value === undefined) {
     return undefined;
@@ -787,9 +805,8 @@ export function serializeViewerState(state: Partial<ViewerState>, removeDefaults
     [ViewerStateKeys.Brightness]: state.brightness?.toString(),
     [ViewerStateKeys.Density]: state.density?.toString(),
     [ViewerStateKeys.Interpolation]: serializeBoolean(state.interpolationEnabled),
-    [ViewerStateKeys.Region]:
-      state.region && `${state.region.x.join(":")},${state.region.y.join(":")},${state.region.z.join(":")}`,
-    [ViewerStateKeys.Slice]: state.slice && `${state.slice.x},${state.slice.y},${state.slice.z}`,
+    [ViewerStateKeys.Region]: state.region && serializeRegion(state.region),
+    [ViewerStateKeys.Slice]: state.slice && serializeSlice(state.slice),
     [ViewerStateKeys.Levels]: state.levels?.join(","),
     [ViewerStateKeys.Time]: state.time?.toString(),
     [ViewerStateKeys.CameraState]: