Unsend and remove all Facebook Messenger messages

del-fb-msgs.js

const SHORT_DELAY = 100;
const MEDIUM_DELAY = 250;
const LONG_DELAY = 500;

let messageChatIdx = 0
let isRunning = false
let exceptionsInARow = 0

const exceptionsInARowUntilNextChat = 40

async function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

async function __getLastMessageMoreIcon() {
  const elements = document.querySelectorAll('div[aria-label="More"]')
  const lastElement = elements[elements.length - 1]
  return lastElement
}

async function __unsendMessage() {
  const element = document.querySelector('div[aria-label="Remove message"]');
  if (element) {
    await sleep(SHORT_DELAY);
    element.click();
    await sleep(SHORT_DELAY);
    const removeButton = await __getRemoveButton();
    await sleep(SHORT_DELAY);
    removeButton.click();
  }
}

async function __findElementsByAriaLabel(label) {
  const elements = document.querySelectorAll(`[aria-label="${label}"]`);
  return Array.from(elements);
}

async function __findElementsByAriaLabelSubstring(substring) {
  const elements = document.querySelectorAll('[aria-label]');
  const retval = Array.from(elements).filter(el =>
    el.getAttribute('aria-label').includes(substring)
  );
  return retval
}

async function __findElementByAriaLabel(label) {
  const elements = document.querySelectorAll(`[aria-label="${label}"]`);
  if (Array.isArray(elements) && elements.length > 0) {
    return elements[0]
  }
  return elements
}

async function __getRemoveButton() {
  const elems = Array.from(await __findElementsByAriaLabel("Remove"))
  if (elems.length === 0) {
    console.warn("No remove button found")
    return
  }
  for (let i = 0; i < elems.length; i++) {
    const elem = elems[i]
    if (elem.ariaDisabled === 'true') {
      continue
    }
    if (elem.textContent === "Remove") {
      return elem
    }
  }
}

async function __triggerMouseHover(element) {
  const mouseOverEvent = new MouseEvent('mouseover', {
    bubbles: true,
    cancelable: true,
    view: window,
  });
  element.dispatchEvent(mouseOverEvent);
}

async function __triggerMouseHoverExit(element) {
  const mouseOutEvent = new MouseEvent('mouseout', {
    bubbles: true,
    cancelable: true,
    view: window,
  });
  element.dispatchEvent(mouseOutEvent);
}

async function __unsendLastMessage() {
  await sleep(SHORT_DELAY)
  const moreIcon = await __getLastMessageMoreIcon()
  moreIcon.click()
  await sleep(SHORT_DELAY)
  await __unsendMessage()
  await sleep(SHORT_DELAY)
}

async function deleteLastMessage() {
  await sleep(SHORT_DELAY)

  let elems = await getAllMessageElements()
  console.log(elems)

  let lastElement = elems[elems.length - 1]
  const lastElementText = lastElement?.textContent || ""
  console.log("lastElement: ", lastElement)

  const children = []
  lastElement.childNodes.forEach((childNode) => {
    children.push(childNode)
  })

  const targetElements = [lastElement].concat(...children)
  console.log("targetElements: ", targetElements)

  targetElements.forEach(async (elem) => {
    try {
      await __triggerMouseHover(elem)
    } catch { }
  })

  await sleep(SHORT_DELAY)

  try {
    await __unsendLastMessage()
  } catch (e) {
    console.log("error", e)
  }
  await sleep(SHORT_DELAY)


  targetElements.forEach(async (elem) => {
    try {
      await __triggerMouseHoverExit(elem)
    } catch { }
  })

  await sleep(MEDIUM_DELAY)

  elems = await getAllMessageElements()
  const newLastElement = elems[elems.length - 1]

  if (lastElement === newLastElement && lastElementText === newLastElement.textContent) {
    lastElement?.remove()
  }

  await sleep(SHORT_DELAY)

}

async function getAllMessageElements() {
  let conversationRoot = await __findElementsByAriaLabelSubstring("Conversation with")
  if (conversationRoot.length === 0) {
    console.warn("No conversation root found")
    return
  }
  conversationRoot = conversationRoot[0]
  const elems = conversationRoot.querySelectorAll('div[role="row"]')
  return Array.from(elems)
}

async function removeErrorMessages() {
  // get all DOM elements <div role="presentation">
  const elems = Array.from(document.querySelectorAll('div[role="presentation"]'))
  elems.forEach(async (elem) => {
    if (elem && elem.textContent === 'Error displaying this message') {
      elem?.remove()
      await sleep(SHORT_DELAY)
    }
  })
}

async function clickOnChat(chatElem) {
  const iterations = 5
  for (let i = 0; i < iterations; i++) {
    chatElem = chatElem.childNodes[0]
  }
  chatElem.scrollIntoView()
  await sleep(SHORT_DELAY)
  chatElem.click()
  await sleep(LONG_DELAY)
}

async function getMessageChats() {
  let elem = await __findElementsByAriaLabel("Chats")
  const idx = elem.length - 1
  elem = elem?.[idx]
  while (elem.childNodes.length == 2 || elem.childNodes.length == 1) {
    const idx = elem.childNodes.length - 1
    const target = elem?.childNodes?.[idx]
    if (target) {
      elem = target
    }
  }
  return Array.from(elem.childNodes)
}

async function Main(loopForever = false) {
  isRunning = true
  console.log("Starting... to stop, issue `isRunning = false`")
  while (isRunning) {

    if (exceptionsInARow > exceptionsInARowUntilNextChat) {
      messageChatIdx++
      try {
        // we probably unsent all the messages
        const chats = await getMessageChats()
        if (messageChatIdx >= chats.length) {
          console.log("Processed all chats!")
          isRunning = false
          return
        }
        await clickOnChat(chats[messageChatIdx])
        exceptionsInARow = 0

      } catch (e) {
        console.log(e)
        exceptionsInARow++
      }
    }

    try {
      console.count("Deleting last message")
      await deleteLastMessage()
      exceptionsInARow = 0
    } catch (e) {
      console.log(e)
      exceptionsInARow++
    }
    await sleep(SHORT_DELAY)
    await removeErrorMessages()
  }
  if (loopForever) {
    await Restart(loopForever)
  }
  console.log("Done!")
}

async function Restart(loopForever = false) {
  // reset globals
  messageChatIdx = 0
  isRunning = false
  exceptionsInARow = 0
  const chats = await getMessageChats()
  await clickOnChat(chats[messageChatIdx]) // go back to first chat
  await Main(loopForever) // process it again
}

it stopped working due to changes in UI so i made a fix. hope its ok. newer version works as of 8/22/2025 (25.8.2025) on:
https://github.com/vandakdominik/Messenger-massage-unsender-removal/tree/main

No worries, feel free to do whatever you want with the code