Messages can use several gigabytes on an iPhone because every photo, video, GIF, and audio clip you send or receive is stored on the device. To trim it, open Settings > General > iPhone Storage > Messages, use Review Large Attachments to delete the heaviest items, and turn on auto-delete after 1 year so old threads stop piling up. Your conversations stay intact — you are only removing bulky media.
TL;DR
- Messages stores all sent/received photos, videos, and GIFs on the device.
- Settings > General > iPhone Storage > Messages > Review Large Attachments finds the heavy ones.
- Set Settings > Messages > Keep Messages > 1 Year to auto-trim old threads.
- Deleting attachments does not delete the conversation text.
- Group chats full of forwarded clips are usually the worst offenders.
Why is Messages using so much storage?
iMessage keeps a copy of every attachment on your phone — years of shared photos, screen recordings, memes, and voice clips. Individually they look trivial; across active group chats they reach gigabytes. Unlike streaming media, these never expire on their own unless you tell Messages to auto-delete, so a multi-year history just accumulates.
How to find and trim large attachments
- Open Settings > General > iPhone Storage.
- Tap Messages.
- Under Documents & Data, tap Review Large Attachments (Photos, Videos, GIFs/Stickers).
- Tap Edit, select the bulky items, and delete. This removes the files but keeps the conversation.
You can also open a specific chat, tap the contact name at the top, and scroll the photo/attachment grid to clear media from one heavy thread.
Stop it building back up
Set messages to expire automatically:
- Settings > Messages > Keep Messages.
- Choose 1 Year (or 30 Days) instead of Forever.
iOS will offer to delete older messages and their attachments once. After that, threads self-trim and Messages storage stays under control.
What iOS does natively, and where it stops
Review Large Attachments and Keep Messages are Apple's own tools and they do the core job — use them first. Where iOS stops: it will not group the same forwarded clip that landed in five chats, or show Messages media alongside the duplicate photos and videos elsewhere on your phone. Messages is usually one piece of a bigger media-bloat picture.
Clear the whole media picture at once
Once Messages is trimmed, the remaining bulk is almost always large videos and duplicate photos in your camera roll. Cleanor for iPhone surfaces those on-device and shows the space each frees before you confirm — nothing uploaded. For the full routine, see the free up iPhone space guide.
What this cannot do
Deleting an attachment in Messages does not remove it from the other person's device, and once deleted it is not recoverable from the chat unless it was saved to Photos. Save anything important before clearing.
FAQ
How do I free up Messages storage on iPhone?
Go to Settings > General > iPhone Storage > Messages > Review Large Attachments, delete the heavy photos and videos, and set Keep Messages to 1 Year so old threads auto-trim.
Does deleting attachments delete the conversation?
No. Removing attachments clears the media files but keeps the message text and the thread itself.
Why is Messages using gigabytes?
Because iMessage stores every photo, video, GIF, and voice clip you send or receive. Years of group-chat media add up to gigabytes that never expire unless you auto-delete.
Will "Keep Messages: 1 Year" delete important texts?
It removes messages and attachments older than a year. Save anything you need to keep first; recent conversations are unaffected.
Next: iPhone storage full but nothing to delete and iPhone Photos using 80GB? How to cut it safely. To clear the whole media picture in one pass, get Cleanor for iPhone.