diff --git a/snippets/allUnique.md b/snippets/allUnique.md
new file mode 100644
index 000000000..bde0d3dc9
--- /dev/null
+++ b/snippets/allUnique.md
@@ -0,0 +1,18 @@
+---
+title: allUnique
+tags: array,beginner
+---
+
+Checks if all elements in an array are unique.
+
+- Create a new `Set` from the mapped values to keep only unique occurences.
+- Use `Array.prototype.length` and `Set.prototype.size` to compare the length of the unique values to the original array.
+
+```js
+const allUnique = arr => arr.length === new Set(arr).size;
+```
+
+```js
+allUnique([1, 2, 3, 4]); // true
+allUnique([1, 1, 2, 3]); // false
+```