Why attachments pile up and slow your phone down

Large attachments — photos, videos, and files sent through Messages, Mail, or apps like WhatsApp — stay on your iPhone even after you've read them. Over months, they add up to gigabytes of storage that your phone could use for updates, new apps, or actual photos you want to keep. Deleting them is straightforward once you know where they hide, because iPhone doesn't always make it obvious that you're storing a copy of something someone else sent you.

The reason attachments stick around is that your phone treats them like any other file. When you receive a photo in a text message, iPhone saves it to your device. When you read a PDF in Mail, it stays there. Your phone doesn't automatically clean these up, so they accumulate in the background — especially if you use messaging apps heavily or get a lot of work emails with documents.

Key Takeaways

  • Attachments in Messages, Mail, and third-party apps each store separately, so you may need to delete from multiple places to free up real space.
  • Deleting a message or email usually deletes its attachment, but some apps like WhatsApp and Telegram keep their own attachment folders that survive message deletion.
  • The fastest way to see how much space attachments are using is to open Settings, tap General, then Storage, where each app shows its size.
  • Clearing an app's cache through Settings does not delete attachments — you must delete them manually or reinstall the app to remove them completely.

Check how much space attachments are actually using

Before you start deleting, it helps to see which apps are hoarding the most. Open Settings, then tap General, then iPhone Storage. Scroll through the list and look for the apps you use most — Messages, Mail, WhatsApp, Telegram, or whatever you message with. The number next to each app shows total storage, including all attachments it has saved.

Tap on any app to see a breakdown. For Messages and Mail, you'll see the app size itself plus "Documents & Data" — that's where attachments live. If Documents & Data is much larger than the app itself, attachments are the problem. For third-party messaging apps, the entire size often includes attachments because these apps bundle everything together.

Delete attachments from Messages

Open the Messages app and find a conversation with large files — usually photos or videos. Press and hold the message that contains the attachment you want to remove. A menu appears. Tap More (three dots on some iPhones, or just labeled "More"). Select additional messages if you want to delete several at once, then tap the trash icon at the bottom right and confirm.

This deletes the entire message, including the attachment. If you want to keep the message but remove only the attachment, you cannot do that directly in Messages — you have to delete the whole message. However, if the attachment is a photo or video, you can save it to your Photos app first, then delete the message. That way you keep the file but free up the space Messages was using to store it.

For a faster cleanup of old conversations, swipe left on a conversation thread and tap Delete. This removes all messages and attachments in that thread at once. This is useful if you have old group chats or work conversations full of files you no longer need.

Delete attachments from Mail

Open Mail and navigate to the folder containing emails with large attachments — usually Inbox or a work folder. Swipe left on an email and tap the trash icon. The email and its attachments are deleted. If you want to keep the email but remove the attachment, you cannot do that in Mail either — deletion removes the whole message.

If you receive a lot of emails with attachments you want to keep the content of but not the file, open the email, tap and hold the attachment, and choose Save to Files or Save Image. This copies the attachment to your Files app or Photos app. Then delete the email from Mail. You've kept the file but freed up the space Mail was using.

To bulk-delete old emails, tap Edit in the top left of any folder, select multiple emails by tapping the circles next to them, then tap Delete. This is faster than swiping one at a time, especially if you have months of old messages to clear out.

Clear attachments from WhatsApp, Telegram, and other messaging apps

These apps store attachments in their own folders, separate from the messages themselves. Deleting a message does not always delete the file. Open WhatsApp, tap Settings (bottom right), then Storage and Data. You'll see how much space the app is using. Tap Manage Storage to see conversations ranked by size.

Tap a conversation to see what's taking up space — usually photos and videos. You can delete individual items by swiping left and tapping delete, or delete the entire conversation. The app will ask if you want to delete the chat and media; choose yes to both to free up the most space.

For Telegram, open the app, tap Settings, then Data and Storage. Tap Storage Usage to see which chats are largest. Open a chat and swipe left on a message to delete it, or use Clear Chat to remove all messages and attachments at once. For other messaging apps like Facebook Messenger or Signal, look for a Storage or Data section in Settings — the layout varies, but the principle is the same.

Use iCloud Photos to move attachments off your phone

If you have photos or videos in Messages that you want to keep but not store on your phone, enable iCloud Photos. Open Settings, tap your name at the top, then iCloud, then Photos. Turn on iCloud Photos. Your phone will upload all photos to iCloud and can store only thumbnails locally, freeing up gigabytes of space.

This works for photos you've taken, but not for attachments in Messages or Mail — those stay on your phone. However, if you save photo attachments to your Photos app first (by tapping and holding and choosing Save), then enable iCloud Photos, those will move to iCloud and off your phone.

Be aware that iCloud Photos requires an iCloud+ subscription if you have more than 5 GB of photos. Check your iCloud storage before enabling it — open Settings, tap your name, then iCloud, then Manage Storage to see what you're using.

Reinstall apps to remove all cached attachments at once

If an app like WhatsApp or Telegram is using several gigabytes and you want a clean slate, you can delete and reinstall it. This removes all cached files and attachments the app has stored. Open Settings, tap General, then iPhone Storage, find the app, and tap Offload App. This removes the app but keeps your data. Then tap Reinstall App.

When you reinstall, the app will re-read your chat history from its servers (if it syncs to the cloud, like WhatsApp and Telegram do). However, old attachments may not re-read automatically — they'll only appear if you scroll back up in a conversation. This is the most aggressive way to free up space, but it works if the app has accumulated years of cached files.

Do not use "Delete App" instead of "Offload App" unless you're certain you have backups of your chats elsewhere. Offload is safer because it keeps your data; Delete removes everything.

Frequently Asked Questions

Will deleting a message from my phone also delete it from the other person's phone?

No. Deleting a message from your iPhone only removes it from your device. The other person still has it on theirs. In some apps like iMessage, you can use "Edit" or "Unsend" to remove a message from both phones within a short time window, but regular deletion only affects your copy.

Can I delete just the attachment and keep the message?

Not directly in Messages or Mail — you have to delete the entire message. However, you can save the attachment to your Photos or Files app first, then delete the message. For third-party apps like WhatsApp, you can sometimes delete individual files while keeping the message, depending on the app's design.

Why does clearing cache in Settings not remove my attachments?

Cache is temporary data the app uses to run faster. Attachments are files you've received and saved. They're stored separately, so clearing cache does not touch them. You must delete attachments manually through the app or reinstall the app entirely to remove them.

If I delete an attachment, can I get it back?

Once deleted, attachments are gone unless you have a backup. If you back up your iPhone to iCloud or a computer regularly, you could restore from that backup, but that would restore your entire phone to an earlier date. If the attachment is important, save it to your Photos or Files app before deleting the message.

How often should I delete attachments to keep my phone running smoothly?

There's no fixed schedule. Check your iPhone Storage every few months — if any app is using more than a gigabyte or two, it's time to clean up. Messaging apps and Mail tend to accumulate fastest, especially if you use them for work or group chats.