How to Find Which App Is Using the Most Storage on Your Phone
To find which app is using the most storage, open Settings > General > iPhone Storage on an iPhone or Settings > Storage (then tap Apps) on Android, where every app is listed largest-first with its exact size. This guide is for anyone whose phone is suddenly full and who wants to see the real culprit before deleting photos they care about.
TL;DR
- iPhone: Settings > General > iPhone Storage sorts apps by size automatically.
- Android: Settings > Storage > Apps (or Apps > sort by size on Samsung/Pixel).
- The biggest number is usually "App Size + Documents & Data" — the data half is often cache and downloads, not the app itself.
- Photos, WhatsApp, and streaming apps (Spotify, YouTube, Netflix) are the usual top offenders.
- Clearing cache and downloads frees space without deleting the app or your account.
How do I see which app uses the most storage on iPhone?
iOS does the sorting for you. There is no need for a separate tool to rank your apps.
- Open Settings > General > iPhone Storage.
- Wait a few seconds for the bar chart and list to finish calculating.
- Scroll the list — apps are shown largest first, with the size next to each one.
- Tap any app to see its breakdown: App Size (the program) versus Documents & Data (your downloads, cache, and offline content).
The top of that list is almost always Photos, followed by messaging and streaming apps. Tapping into an app gives you two safe actions: Offload App (removes the app but keeps its data) and Delete App (removes both). For a deeper look at the murky "Documents & Data" number, see what is System Data on iPhone and Android and can you delete it.
How do I check app storage on Android?
Android varies a little by brand, but the path is short on every recent version (Android 13, 14, and 15).
- Open Settings > Storage.
- Tap Apps (on some phones this is Apps & data or just Other apps).
- Use the sort control at the top and choose Size to rank largest-first.
- Tap any app to open its App info > Storage & cache screen.
There you will see two figures that matter: App size / Data and Cache. On Samsung the route is Settings > Battery and device care > Storage > Apps; on Pixel it is Settings > Storage > Apps. Tapping Clear cache is safe and reversible — it never logs you out or deletes your account. Tapping Clear storage (or Clear data) wipes the app back to a fresh install, so use that only deliberately.
What do the storage numbers actually mean?
A single big number hides three very different things. Knowing which is which tells you whether to clear, offload, or delete.
| What you see | What it really is | Safe to clear? |
|---|---|---|
| App Size (iOS) / App size (Android) | The program's own files | No — clearing means deleting the app |
| Documents & Data (iOS) / Data (Android) | Logins, settings, your downloads | Partly — losing it may sign you out |
| Cache | Temporary files the app can rebuild | Yes — always safe |
| Photos & Videos | Your actual media library | Only if backed up first |
| Downloads (offline music, maps, video) | Content you chose to save | Yes — re-downloadable |
The practical takeaway: a 9 GB messaging app is rarely 9 GB of "app." It is years of received photos, videos, and voice notes. That is data you can prune without uninstalling. If you are unsure what is safe to remove first across the whole phone, start with storage full, what should I delete first.
Which apps are usually the biggest storage hogs?
Across most phones the same handful of apps dominate the list. Here is what tends to take the space and the quickest fix for each.
- Photos / Gallery — your camera roll plus screenshots and duplicates. Back up to the cloud, then thin out. See how to delete photos from your phone but keep them in the cloud.
- WhatsApp / Telegram — received media piles up silently. Clear it without losing chats via how to clear WhatsApp and Telegram storage without losing your chats.
- Spotify / YouTube / Netflix — offline downloads and stream cache. Open each app's own Settings > Storage and delete downloads or clear cache there.
- Instagram / TikTok — heavy media caches that rebuild fast. Clearing them is harmless.
- Maps — offline regions can be hundreds of MB. Remove old downloaded areas you no longer travel to.
Many apps cache far more than they need. Clearing it is safe, though it usually comes back; see what is app cache and when is it safe to clear.
Is it safe to clear an app's data to free space?
Mostly yes, with one important distinction between two buttons that sound similar.
What the OS does natively: Both iOS and Android let you clear cache and offloaded files without touching your account. On Android, Clear cache removes only rebuildable temporary files. On iOS, Offload App deletes the program but preserves your documents and data, so reinstalling restores everything. These actions are reversible and low-risk.
What "Clear storage / Clear data" does: This is the heavier hammer. It returns the app to a fresh-install state — you will be signed out, and any in-app content not backed up to the cloud (some chat histories, locally saved files) can be lost. Use it only when an app is misbehaving or you have confirmed a backup.
What Cleanor adds: Cleanor scans your library to surface the space the OS hides inside that big "Photos" number — duplicate and near-identical shots, large videos, and screenshots — and lets you review and remove them in batches before they sync. It works with your photo library rather than around it, so deletions happen through the system, where they remain recoverable for the standard recently-deleted window.
What Cleanor cannot do: It cannot reach inside another app's private cache (no app on iOS or Android can — that is by design), it cannot magically shrink an app's own program files, and it will not delete anything without your confirmation. It is a way to find and clear the photo and video bulk faster, not a shortcut around the operating system's protections. If you are weighing whether any cleaner is trustworthy, read the truth about cleaner apps, are they safe to use.
FAQ
Why does one app show a huge size when I barely use it?
The size you see usually includes Documents & Data or downloaded content, not just the app. A messaging or streaming app may store years of received media or offline files. Open the app's own storage settings to clear cache and downloads without uninstalling.
Does deleting the biggest app actually free that much space?
It frees the app size plus its data, but if most of that number is your photos or chats, deleting the app does not save those — and you may lose access. It is usually better to clear cache and prune downloads first, then decide.
Will clearing an app's cache log me out or delete my messages?
Clearing cache does neither — it only removes temporary files the app rebuilds. Clearing storage / data is different: that signs you out and can erase local content. Stick to clearing cache unless you intend a full reset.
Why is Photos always at the top of my storage list?
Because it holds every photo, video, screenshot, and duplicate you have ever taken, often gigabytes of it. Backing up to iCloud or Google Photos and removing duplicates is the single biggest win. Learn the difference in duplicate vs similar photos, what to delete to free up space.
Where to go from here
Once you know which app is the culprit, the fix depends on whether the bulk is cache (clear it), downloads (delete them), or photos and videos (back up, then prune). For a guided, whole-phone approach that handles the photo and video bulk safely, see Cleanor's clean-up-phone-storage solution and the Cleanor for iOS app. To understand whether freeing space even helps performance, read does freeing up space make your phone faster, the 10% rule.