Device migration is when photo libraries get lost. Not dramatically — nobody watches 30,000 photos disappear. It happens quietly: a transfer that reported success but skipped 400 files, an album structure that didn't come across, dates that all reset to the day of the move, an old phone traded in before anyone verified the new one had everything.
The precautions are simple and most people skip them because the transfer appeared to work.
The one rule
Never erase, trade in, or wipe the old device until you have verified the new one.
Verified means: you counted the photos on both, and you opened several specific ones on the new device. Not "the transfer said it finished."
Carriers and stores will push you to trade in during the same visit. Take the phone home. Verify over a few days. Trade in next week. The discount is not worth the risk, and a wiped phone is not recoverable.
Before any migration: three checks
1. Count what you have. Open your photo app and find the total item count. iPhone: Photos → Library, scroll to the bottom. Google Photos: settings shows the backed-up count. On a computer, right-click the folder and check Properties or Get Info.
Write the number down. This is the only way to know afterward whether everything came across.
2. Make an independent backup. Not a sync — an actual copy on an external drive that isn't part of the migration. If the transfer goes wrong, this is what saves you.
3. Note what isn't a photo. Albums, favorites, edits, face names, shared albums, and Live Photos are all data about your photos, and each moves differently. Some won't survive certain transfers at all. Knowing that ahead of time prevents the discovery three weeks later.
iPhone to iPhone
The easiest case.
Quick Start (holding the phones near each other during setup) or an iCloud restore will bring everything: photos, albums, edits, favorites, face names.
Watch for: if you use iCloud Photos with Optimize iPhone Storage, your photos live in the cloud and the new phone downloads them over time. The library will look complete before it actually is. Leave the phone on Wi-Fi and plugged in overnight, then check Settings → Photos for a download progress indicator before assuming you're done.
If you don't use iCloud Photos, a wired transfer through a computer is more reliable than trying to move a large library over Wi-Fi.
Android to Android
Google Photos backup carries everything if you were backing up. Sign in on the new phone and your library is there.
The catch: photos in device folders that weren't set to back up — screenshots, WhatsApp images, downloads — may not be included. Check Google Photos → Settings → Back up device folders before you switch to see what was actually covered.
For anything not backed up, transfer the folders directly with a cable or the manufacturer's transfer tool.
iPhone to Android
The most error-prone common migration.
The reliable path:
- On the iPhone, make sure everything is in iCloud Photos and fully uploaded.
- Use Apple's Transfer a Copy of Your Data tool (at privacy.apple.com) to move photos and videos directly to Google Photos. Apple provides this specifically for the switch.
- Alternatively, install Google Photos on the iPhone, let it back up the entire library, then sign in on the Android phone.
Option 3 is slower but more transparent — you can watch the upload count.
What won't come across:
- Live Photos become still images or separate video files
- Edits may flatten — you get the edited version, not the ability to revert
- Albums transfer inconsistently depending on method
- Face names don't transfer at all; you'll re-tag people on the new phone
- HEIC files may or may not convert; Android handles them now, but some apps still don't
Before switching, set iPhone to Settings → Photos → Transfer to Mac or PC → Automatic, so any direct transfers produce JPEGs rather than HEIC.
Android to iPhone
Apple's Move to iOS app handles this during iPhone setup. It transfers photos and videos over a direct Wi-Fi connection between the phones.
Watch for: it only runs during initial setup. If you've already finished setting up the iPhone, you'd need to erase it and start over, or transfer manually.
Alternative that's often easier: install Google Photos on the new iPhone and access your library there. You're not moving anything — the library stays where it is and works on both. Then download originals into Apple Photos if and when you want them locally.
Mac to Mac
Migration Assistant moves the Photos library intact, including albums, edits, and face names.
If moving manually: the Photos Library is a single package file, usually in your Pictures folder. Copy the whole thing to the new Mac's Pictures folder, then hold Option while opening Photos to choose it.
Do not open the package and copy files out of it. The internal structure is a database, and copying pieces of it produces a broken library.
Mac to Windows, or Windows to Mac
The library format doesn't cross platforms, so you export files rather than move a library.
From Mac: open Photos, select all, then File → Export → Export Unmodified Originals if you want originals with metadata intact, or Export Photos if you want your edits baked in.
Critically: in the export dialog, set Subfolder Format to "Moment Name" or year, and File Naming to use the title or sequential naming. Otherwise you get 30,000 files in one flat folder, which is technically a successful export and practically a disaster.
From Windows: photos are already ordinary files in folders. Copy the folders.
What you lose either way: albums, favorites, face names, and the ability to revert edits. These live in the app's database, not in the files. Export the folder structure you want to keep as folders before you move.
Cloud service to cloud service
Google Photos out: use Google Takeout. Request photos specifically, in ZIP files no larger than 10 GB or the download will fail on most connections. Metadata arrives in separate JSON files alongside the images rather than embedded — reuniting them takes a tool and some patience.
Apple Photos out: privacy.apple.com offers a data export, or export from the Mac app, which is cleaner.
Amazon Photos out: download through the web interface or desktop app.
The general problem: every service makes getting in easy and getting out tedious. Budget real time, and don't cancel the old subscription until the new library is verified. Services delete data after cancellation, sometimes faster than you'd expect.
The verification checklist
After any migration, before you wipe or trade in anything:
1. Compare counts. Total items on the new device versus the number you wrote down. A small difference may be legitimate — some transfers count Live Photos as one item instead of two. A difference of hundreds is a problem.
2. Check the oldest photo. Sort by date, oldest first. Open the very first photo. If your library starts in 2009 and the new device starts in 2015, six years didn't make it.
3. Check the newest. Same, from the other end.
4. Open five specific memories. Not random ones — specific photos you know exist. A wedding, a particular trip, a grandparent. Search for them. Open them full-screen and confirm they're the real photo and not a placeholder or a broken thumbnail.
5. Check dates. Are photos in the right chronological order, or did everything reset to the migration date? If dates flattened, the fix is far easier now than after you've added another year of photos on top.
6. Check videos specifically. Videos are the most commonly dropped item in transfers because of their size. Count them separately and play a few.
7. Check albums and favorites. If these mattered to you, confirm they exist. If they didn't come across, decide now whether to rebuild them or let them go.
8. Wait a week. Use the new device normally. Problems tend to surface through ordinary use rather than through checking.
Only then wipe the old device.
Wiping the old device
Once verified:
Phones: sign out of your account first (iCloud on iPhone, Google on Android) — this releases activation locks that otherwise make the device unusable for the next owner. Then Erase All Content and Settings.
Computers: sign out of accounts, deauthorize any licensed software, then erase the drive. On modern encrypted drives, a standard erase is sufficient.
External drives you're retiring: if they held your photo library, erase them properly before disposal. A quick format leaves data recoverable.
The migration that goes wrong
If you discover something missing after the fact:
Don't panic and don't start moving files. Additional copying can overwrite things.
Check the old device first if you still have it. This is the entire reason for the rule at the top of this article.
Check the cloud service's trash. Deleted items typically persist 30 to 60 days.
Check your independent backup — the copy you made before starting.
Check for a partial transfer. Sometimes files arrived but the app didn't index them. On a computer, search the drive for image file types rather than browsing the app.
Doing it the easy way, permanently
The reason migration is stressful is that the library lives on a device. Devices get replaced; libraries shouldn't have to move each time.
A better arrangement: keep the authoritative library on an external drive or NAS at home, backed up properly. Phones and laptops sync a working copy from it. When a device is replaced, nothing moves — you just point the new one at the same library.
Set up that way, a new phone is a fifteen-minute exercise instead of a weekend and a low-grade fear that something got left behind.
Next in this series: External Drive vs NAS vs Cloud for Photo Storage