Disabling and deleting Messages in iCloud will remove all your conversations from your iCloud account. As a result, your text conversations will no longer sync across your devices.
With Messages in iCloud, anything you delete from iPhone is also deleted from your other Apple devices where Messages in iCloud is turned on. Deleting messages changes only your own Messages conversations, not those of your recipients.
Delete old text messages
You'll be surprised to see how much storage space your text messages take on your smartphone. You may not even realize those messages are being saved to your phone. Don't worry, you can delete them. Be sure to delete messages with photos and videos first — they chew up the most space.
Disabling Messages in iCloud does not delete messages from your device. If you are still worried about this, you should back up your iPhone first. Backups contain all messages, along with everything else important on the device.
What's likely stealing all the storage space are all the attachments you send and receive — audio, photos, stickers, videos, GIFs, and files. With Messages on iCloud, Apple stores your entire messaging history on its servers.
Clear Storage is an app feature that will allow you to free up space on your devices by deleting unwanted or older files such as images, audio, and video messages sent or opened in message groups.
Turning off iMessage will NOT delete the iMessages currently on the phone. Turning off iMessage will NOT delete the iMessages currently on the phone.
When you disable and delete your iCloud messages, all your chats will download to the iPhone automatically so that you don't lose data. In addition, even after removing the text messages from iCloud, you've got 30 days to restore them before they are deleted permanently.
Turning off iMessage just stops the transport of messages via wifi. If you're talking about an iPhone, it will revert to standard SMS, your text records remain intact and continue to accumulate as you continue to use it.
When you delete a piece of data from your device — a photo, video, text or document — it doesn't vanish. Instead, your device labels that space as available to be overwritten by new information.
Deleting Messages does not free up storage
Look for the Messages containing attachments. Delete entire message discussions. If you could delete the Messages app it would clear the lot but you cannot.
Videos, photos and large email attachments are large files that fill up storage space quickly. Apps like Mail, Contacts, Calendar, Reminders and Notes automatically access the cloud and store additional data there.
When you set up iCloud for Messages, your messages are stored in the cloud instead of locally on your device. You can see them on any device that's set up for iCloud and Messages, including your iPhone, iPad, iPod touch, and Mac.
This happens when your Apple ID is activated with iMessage and the "Start new conversations from" setting is set to your email address instead of your phone number. To change this, simply navigate to Settings > Messages > Send & Receive and configure the settings to start new conversations from your phone number.
On your iPhone, iPad, or iPod touch, go to Settings > [your name] > iCloud. Do one of the following: iOS 16, iPadOS 16, or later: Tap Show All, tap Messages, then turn on Sync this [device]. iOS 15, iPadOS 15, or earlier: Turn on Messages.
You can do this by navigating to Messages > Edit or Filters > Show Recently Deleted. From there, you will see a list of any deleted messages that are available to recover. You can recover all messages or just certain ones that you select.
Remove videos, books, and music stored on your phone
Sometimes what's taking up the most amount of storage are the data and documents stored within an app on your phone. You can find out if that's the case by once again heading to Settings > General > iPhone Storage and then clicking on an app.
It's not bad to clear your cached data now and then. Some refer to this data as “junk files,” meaning it just sits and piles up on your device. Clearing the cache helps keep things clean, but don't rely on it as a solid method for making new space.
Clear the cache
To clear cached data from a single or specific program, just go to Settings> Applications>Application Manager and tap on the app, of which the cached data you want to remove. In the information menu, tap on Storage and then “Clear Cache” to remove the relative cached files.