diff --git a/packages/rrweb-snapshot/src/utils.ts b/packages/rrweb-snapshot/src/utils.ts
index a443cb96c1..110cf1a735 100644
--- a/packages/rrweb-snapshot/src/utils.ts
+++ b/packages/rrweb-snapshot/src/utils.ts
@@ -256,6 +256,7 @@ export function isNodeMetaEqual(a: serializedNode, b: serializedNode): boolean {
  * where passwords should be masked.
  */
 export function getInputType(element: HTMLElement): Lowercase<string> | null {
+  // when omitting the type of input element(e.g. <input />), the type is treated as text
   const type = (element as HTMLInputElement).type;
 
   return element.hasAttribute('data-rr-is-password')