DB Labs
The Short Answer
iMessage storage is almost entirely attachments — photos, videos, GIFs, audio messages, and shared links. To clear it: go to Settings → General → iPhone Storage → Messages → Review Large Attachments and delete the biggest files. Then prevent future buildup by setting Settings → Messages → Keep Messages → 1 Year instead of Forever. Deleting old conversation threads is also effective — each thread takes its attachments with it.
Why iMessage Uses So Much Storage
Every photo, video, voice message, GIF, sticker, and file shared in a conversation is stored locally on your iPhone. Text itself is tiny — thousands of text messages take less than 1 MB. But a single 4K video clip can be 100-200 MB, and a group chat that is active for a year can accumulate thousands of images.
iOS keeps all of this indefinitely by default. If you have the default "Keep Messages: Forever" setting and have used iMessage for several years, it is not unusual to find 5-10 GB stored in Messages.
Check iMessage Storage
Go to Settings → General → iPhone Storage, scroll down to Messages, and tap it. You will see the total storage used. Then tap Review Large Attachments — iOS lists every attachment sorted by size, largest first. This is the most useful view for quickly identifying what is worth deleting.
How to Delete iMessage Attachments
1 Delete via Review Large Attachments
In Settings → General → iPhone Storage → Messages → Review Large Attachments, tap Edit, select the items you want to remove, and tap the trash icon. You can select multiple items at once. This deletes only the selected attachments — the surrounding message text stays intact.
2 Delete Directly from a Conversation
Open a conversation in Messages. Tap the contact name at the top and scroll down to see the media grid (photos and links). Tap See All Photos to view all images in that thread. To delete, go back to the conversation, long-press a specific message containing the attachment, tap More, select it, and tap the trash icon.
3 Delete Entire Conversations
The fastest way to clear a lot of storage is to delete entire old conversations. In the Messages list, swipe left on a conversation and tap Delete. The entire thread — every message and every attachment — is permanently removed. Do this for any old conversations you no longer need.
Enable Auto-Delete for Old Messages
The most important long-term fix is changing the Keep Messages setting. Go to Settings → Messages → Keep Messages. The default is Forever. Change it to 1 Year or 30 Days.
iOS will warn you that older messages will be deleted and ask for confirmation. Once confirmed, messages and their attachments older than your chosen period are automatically removed going forward. This prevents the problem from recurring without any ongoing effort from you.
Auto-Delete Voice Messages
Voice messages are often overlooked but can accumulate significantly. Go to Settings → Messages → Expire under the Audio Messages section and set it to After 2 Minutes. This auto-deletes audio messages 2 minutes after you listen to them, rather than keeping them forever. If you need to keep a specific voice message, you can save it manually before it expires.
What Happens to Photos Saved to Your Camera Roll?
If you tapped Save on any photo received in Messages, that photo exists in two places: in your Messages thread, and in your Photos app. Deleting it from Messages does not remove it from Photos, and vice versa. This means after clearing iMessage storage, you may still have all those photos in your camera roll.
To clean up those camera roll photos efficiently, use Swype Photo Cleaner — swipe through your library and remove the ones you do not need. For more context on all storage categories, see our complete iPhone storage guide.