FF128RelNote: SharedArrayBuffer growable, ArrayBuffer reziable

files/en-us/mozilla/firefox/releases/128/index.md

@@ -27,6 +27,16 @@ This article provides information about the changes in Firefox 128 that affect d
 
 ### JavaScript
 
+- Resizeable {{jsxref("ArrayBuffer")}} and growable {{jsxref("SharedArrayBuffer")}} are now supported, allowing the size of buffers to be changed without having to allocate a new buffer and copy data into it ([Firefox bug 1884150](https://bugzil.la/1884150)).
+  The relevant method and properties are:
+
+  - Grow {{jsxref("SharedArrayBuffer")}} using the {{jsxref("SharedArrayBuffer.prototype.grow()")}} method.
+    The maximum allowed size of the buffer is specified using the `options.maxByteLength` parameter to the [`SharedArrayBuffer()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer/SharedArrayBuffer#maxbytelength).
+    The {{jsxref("SharedArrayBuffer.prototype.growable")}} and {{jsxref("SharedArrayBuffer.prototype.maxByteLength")}} properties indicate whether the buffer can grow, and its maximum allowed size, respectively.
+  - Resize {{jsxref("ArrayBuffer")}} using the {{jsxref("ArrayBuffer.prototype.resize()")}} method.
+    The maximum allowed size of the buffer is specified using the `options.maxByteLength` parameter to the [`ArrayBuffer()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/ArrayBuffer#maxbytelength).
+    The {{jsxref("ArrayBuffer.prototype.resizable")}} and {{jsxref("ArrayBuffer.prototype.maxByteLength")}} properties indicate whether the buffer can be resized, and its maximum allowed size, respectively.
+
 #### Removals
 
 ### SVG