WhatsApp Backup Stuck on Preparing? Fixes for Android and iPhone
Short answer
"Preparing" means WhatsApp is still indexing files, not uploading. It stalls most often because the cloud account is full, battery optimisation has killed the background process, or a very large video is choking the index. Check free space in Google Drive or iCloud first, keep the phone on Wi-Fi, plugged in and awake, and turn off Include videos as a test.
On this page
“Preparing backup” is not the upload stage. It is the phase where WhatsApp walks through every message and every media file on the device, building the archive before anything is sent anywhere. On an account with 40,000 messages and 15GB of media, that scan is genuinely slow — a first backup can sit on this screen for the better part of an hour and still be working normally.
The problem is that a genuinely stalled backup looks identical. The distinction is time: a routine daily backup should clear Preparing in under two minutes. If it has been twenty minutes on an account that has backed up before, something is blocking it.
Check these in order
The causes are roughly ordered by how often they turn out to be responsible.
| Likely cause | Quick check | Platform |
|---|---|---|
| Cloud account is full | Drive or iCloud storage figure | Both |
| Battery optimisation suspended it | Phone sleeping or unplugged | Android mainly |
| One oversized video | Backup size vastly exceeds expectation | Both |
| Network dropped mid-scan | Mobile data, weak Wi-Fi | Both |
| Encrypted backup state confused | Recently enabled or changed | Both |
| Corrupt previous backup | Repeated failures at same point | Both |
Fix one: make sure the cloud has room
A backup cannot complete into a full account, and the error shown is frequently unhelpful rather than explicit about the cause.
Android: go to one.google.com/storage. If the 15GB is full or nearly full, that is very likely your answer. Note that WhatsApp backups themselves now count toward the quota, so a large existing backup can be the reason there is no room for a new one — the full picture is in WhatsApp backup filling your Google storage.
iPhone: go to Settings → [your name] → iCloud → Manage Account Storage. The free tier is 5GB, which a WhatsApp backup will exhaust on its own without difficulty.
If you are short, free space before retrying. Retrying into a full account will simply fail again.
Fix two: remove the battery and sleep restrictions
Android in particular suspends background work aggressively, and a suspended backup appears stuck rather than paused.
- Plug the phone into power.
- Connect to Wi-Fi.
- Keep the screen on — open WhatsApp and leave the backup screen visible.
- Android only: go to Settings → Apps → WhatsApp → Battery and set it to Unrestricted. The wording varies by manufacturer; Samsung phones also have Settings → Battery → Background usage limits, where WhatsApp must not be in the sleeping or deep-sleeping app lists.
On iPhone, check Settings → General → Background App Refresh is on, and that Low Power Mode is off — Low Power Mode blocks iCloud backup activity outright.
These four conditions together resolve a large share of cases on their own, and cost nothing to try.
Fix three: test by excluding videos
One enormous video can stall the indexing phase, and videos are the bulk of most backups anyway.
Android: in Chat backup, turn off Include videos, then tap Back up.
iPhone: in Chats → Chat Backup, turn off Include Videos, then tap Back Up Now.
If the backup completes with videos off, you have identified the cause. You can then either leave videos excluded permanently — a reasonable choice, since they stay on your phone and in your chats either way — or clear the large files and try again with videos on.
The media cleanup method is in cut WhatsApp storage without deleting chats. Removing the top twenty videos frequently fixes a stuck backup and shrinks it substantially at the same time.
Fix four: Wi-Fi versus mobile data
Both platforms default to backing up on Wi-Fi only, which is sensible for data usage but means a dropped Wi-Fi connection halts the process without an obvious message.
Confirm you are actually on Wi-Fi and that the connection is stable. A weak signal that drops intermittently is worse than no connection, because the process keeps restarting.
If your Wi-Fi is unreliable, Android lets you choose Wi-Fi or cellular under Back up over in the Chat backup screen. Be aware of the data cost before doing so — a 6GB backup over mobile data is a significant amount of allowance.
Also worth checking: some public, workplace and hotel networks block the ports cloud backup uses. If the backup works at home but not at the office, that is the explanation, and there is no fix beyond using a different network.
Fix five: toggle end-to-end encrypted backup
If you recently turned on encrypted backup, or changed the password or key, the state can get confused and block the process.
Android: Settings → Chats → Chat backup → End-to-end encrypted backup. iPhone: Settings → Chats → Chat Backup → End-to-End Encrypted Backup.
Turn it off, wait for the change to confirm, run a backup, then turn it back on if you want it.
Before you do this: turning encryption off requires your password or 64-digit key. If you cannot produce it, you cannot turn encryption off, and you also cannot restore that backup on a new phone. If you have lost the key, do not attempt anything else here until you have resolved that — there is no recovery path, by design.
Fix six: force stop and clear cache
A straightforward reset of the app’s running state, without touching your data.
Android: Settings → Apps → WhatsApp → Force stop, then Storage → Clear cache. Reopen WhatsApp and retry.
Critical distinction: on that same screen there is Clear storage (or Clear data on some versions). Do not tap it. It wipes your local chat database and logs you out — the exact outcome you are trying to protect against. Clear cache is safe; Clear storage is not.
iPhone: there is no cache control. Force close WhatsApp by swiping it away from the app switcher, restart the phone, and retry.
Last resort: delete the old backup
If everything above has failed and the failure is consistent, the existing backup may be corrupt and blocking the new one from being written over it.
Read this before proceeding. Deleting the backup removes your only restore point. Your chats stay on the phone and nothing visible changes — but between deleting the old backup and successfully completing a new one, you have no recovery option at all. If the phone is lost, broken, stolen or reset in that window, that message history is unrecoverable. WhatsApp holds no server-side copy.
Do this only if you accept that risk, and ideally export your most important chats first via the chat info screen’s Export chat option.
Android: in Chat backup, tap the Google Account entry, or go to Google Drive → menu → Backups, find the WhatsApp entry and delete it. Then run a fresh backup.
iPhone: Settings → [your name] → iCloud → Manage Account Storage → WhatsApp → Delete Data. Then run a fresh backup.
What not to do
- Do not uninstall WhatsApp to fix a backup problem. Reinstalling restores from the backup you cannot currently create. If the backup is broken, you may lose your chats entirely.
- Do not leave it running for days hoping it resolves. A genuinely stalled backup does not recover on its own. After an hour with no progress on a routine backup, start working through these fixes.
- Do not use third-party WhatsApp backup tools. They require disabling security protections, often need a computer connection with debugging enabled, and several have been vehicles for credential theft.
- Do not change your phone number or move to a new device mid-problem. Resolve the backup first; a transfer without a working backup loses history.
What to expect
Most stuck backups resolve from the first three fixes combined — free cloud space, phone plugged in and awake with battery restrictions removed, and videos excluded as a test. A first-ever backup on a large account genuinely takes 30 to 60 minutes even when working correctly, so patience is part of the fix.
If the backup completes but is uncomfortably large, that is a separate and easier problem to solve — covered in WhatsApp backup filling your Google storage.