Your phone says storage is full, but the photos are the one thing you do not want to lose. On most phones, the photos are not even the main problem. The space is usually eaten by things you will never miss: apps you have not opened in months, message attachments, downloaded files, and full-resolution copies of photos that could safely live in the cloud instead. Work through these steps in order, and check your storage screen after each big step. Do the backup step first.
Step 0: Back up before you delete anything
Make sure your photos exist in at least one place besides this phone: iCloud Photos sync on and up to date, Google Photos backup complete, or — if you use neither — copies on a computer first.
This matters because of one rule that catches people out: when photos are synced, deleting them on the phone deletes them everywhere. iCloud Photos, Google Photos, and Messages in iCloud all sync deletions across your devices. There is no "delete from this phone but keep it on my iPad" button for synced content. Back up first, then tidy with confidence.
Step 1: See exactly what is eating your storage
On iPhone, open Settings, then General, then iPhone Storage, and give it a minute to calculate. You will see a bar showing what is using space, and apps sorted by size, with Apple's own recommendations at the top.
On Android, open Settings, then Storage, then tap a category. Google's help page describes the same idea: storage is where you keep data like music and photos, and the Storage screen shows which categories are biggest.
Note two numbers first: free space, and the three biggest categories. That is your baseline.
Step 2: Offload the apps you have not opened in months
This is the biggest painless win on iPhone. Offloading an app removes the app itself but keeps its documents and data, so you can reinstall it later and pick up where you left off. Turn on the offload recommendation on the iPhone Storage screen, or offload two or three large apps by hand — games and streaming apps are the usual suspects.
On Android, the equivalent is clearing an app's cache. Open Settings, then Apps, then See All Apps, tap the app, then Storage and cache, then Clear cache. Clearing cache deletes temporary data; the app may be slower next time, but your files and logins stay put. Do not tap Clear storage by accident: that permanently deletes all of the app's data. Google's help page makes the same distinction, and it is worth reading twice before you tap.
Step 3: Let the cloud hold the full-resolution photos (iPhone)
With iCloud Photos turned on and Optimize iPhone Storage selected, full-resolution originals live in iCloud and your iPhone keeps smaller, space-saving versions locally when space is needed. You still see every photo, you still scroll through the whole library, and the full original downloads on demand when you open, edit, or share it.
Apple's steps are: tap Settings, tap your name, tap iCloud, then tap Photos. Turn on Sync this iPhone. In iOS 27 or later, tap iPhone Storage, and make sure Optimize iPhone Storage is turned on. Apple says optimisation is on by default with iCloud Photos, but check it anyway — it only works if you have enough iCloud space for the library.
That is the catch. Signing up for iCloud gives you 5 GB of free storage, shared across your devices. If your library is bigger than your iCloud space, optimisation cannot do its job. Check your iCloud space first: Settings, then your name, then iCloud. If iCloud is full, freeing phone space starts with freeing iCloud space, or moving the library to a computer — not with deleting photos.
Step 4: Free up space in Google Photos (Android)
If you back up with Google Photos, you can delete the copies on your phone while the backed-up copies stay in your library. Google's warning comes first and is non-negotiable: before you use this feature, make sure your photos are backed up properly. Photos and videos fewer than 30 days old may be retained on your device even after you run it; they will still be backed up in your library.
The steps are: open the Google Photos app, sign in, tap your account profile photo or initial, then tap Free up space on this device. You will see how much space will be freed. Confirm only after the backup check above. To see your photos afterwards, open photos.google.com or the Google Photos app — the library is still there, the phone copies are not.
Google Photos also has a storage management tool that surfaces items you might want to delete, such as blurry photos, screenshots, and large videos. Use it as a suggestion list, not an instruction: it cannot tell a failed shot from the only photo of a moment that matters. Delete only what you have actually looked at.
Step 5: Merge duplicates, clear recommendations, then messages and downloads
Apple lists two more tidy-ups that cost nothing. With Recommended for You, available in iOS 17 or iPadOS 17 or later, you can check whether there are photos, large files, or backups you might not need anymore. You can also merge duplicate photos and videos: merging keeps one copy and removes the rest, so nothing unique is lost. Do this after Step 3, not before.
Messages are the silent storage hog on both platforms. On iPhone, the storage screen lets you review Messages by category and delete large attachments conversation by conversation — save anything you want to keep first. On Android, open Settings, then Storage, then Free up space, scroll to the category you want, and select files to move to the bin. Items in a trash or recently-deleted folder still take up space until that folder is emptied, and emptying it is permanent, so do not empty a trash folder in a hurry.
While you are here, clear your Downloads folder. On Android you can move files to a computer with a USB cable and then delete them from the phone — the safest route for anything you are unsure about: move it first, delete it second, and only once you have confirmed the copy opens on the computer.
Step 6: Check the number again, and stop when it is enough
Reopen the storage screen and compare the free-space number with your Step 1 baseline. You do not need to chase every last megabyte. A phone with a comfortable margin — enough to take photos, install updates, and receive messages without warnings — is done. If the number barely moved, the problem is probably not photos: check the biggest category from Step 1 again, and whether a single app, a backup, or a full cloud account is the real cause.
One last warning: do not install a "cleaner" app to do this job. No step here needs one, every step is built into the phone already, and handing a third-party app permission to delete your files is a bigger risk than a full storage bar. The built-in screens show you what you are deleting before you delete it — and that is the whole point.
Frequently asked questions
Will Optimize iPhone Storage delete my photos?
No. With iCloud Photos on and Optimize iPhone Storage selected, full-resolution originals stay in iCloud and your iPhone keeps space-saving versions. The original downloads when you open, edit, or share it. It only works if you have enough iCloud space, so check that first.If I delete a photo from my phone, is it gone everywhere?
If the photo is synced — iCloud Photos, Google Photos, or Messages in iCloud — yes, deleting it on one device deletes it on the others. That is why the backup step comes first. If a photo exists only on the phone, deleting it removes that only copy, so copy it to a computer first if it matters.Does clearing an app's cache delete my files or logins?
On Android, Clear cache deletes temporary data only; files and logins stay. Clear storage is different — it permanently deletes all of the app's data. Do not confuse the two.Get a Free Consultation
If your business phones, tablets, or shared devices keep running out of space, get a free consultation. Visuosofts, 174 Wilmslow Road, Manchester M14 5LQ, +44 7387 055617, info@visuosofts.com.
Sources: Apple Support, "Manage your photo and video storage" (support.apple.com, published 1 October 2026); Google Support, "Free up storage on your Android device" and "Free up space on your device" (Google Photos, support.google.com). Menu names vary by device and software version; where Apple gives an iOS 27 wording, it is stated as such.