WhatSave by Jstarzz

A free, open-source Chrome extension (Manifest V3) that bulk downloads media from WhatsApp Web, images, videos, voice notes/audio, and documents, from one or more chats at once, either as loose files or a single ZIP.

Built by Jstarzz. A star on the repo helps other people find it.
Features

No limits and no license key. Everything is unlocked.
Select multiple chats in the popup and it works through each one in turn.
Files save through chrome.downloads (via the background service worker) rather than by clicking a hidden link inside the WhatsApp Web page. Chrome blocks a page from firing off a stream of automatic downloads but does not block an extension doing the same through its downloads API, which is what makes downloading many files back to back possible at all.
Media is fetched fresh from WhatsApp instead of read out of whatever the page happens to have cached, so files save at their original quality.
Downloads run 2, 4, 6, or 8 files at a time rather than strictly one.
Individual files land in Downloads/WA Media Downloads/<Chat Name>/... instead of loose in your Downloads root.
Progress reporting, a bounded log panel so a large batch does not bog down the popup, and "All types" / "Videos only" filter buttons.