Free up Notes storage

Apple Notes stores text plus attachments: scans, photos, drawings, and files. Those attachments are the data. iCloud Notes sync across devices. Notes in On My iPhone live only on this device. Deleting a note is not a cache clear.

See how much space Notes is using

Open the iPhone Settings app.
Tap General > iPhone Storage.
Tap Notes.

iCloud vs On My iPhone

Open Settings > [your name] > iCloud and confirm Notes is on if you want a cloud copy.
In the Notes app, check folder accounts: iCloud versus On My iPhone.

Move anything important out of On My iPhone into iCloud before you delete notes or erase the phone.

Attachments, scans, and drawings

Open a large note.
Tap the attachment, scan, or drawing.
Delete it only if you mean to change the note. Export to Files first if you might need the scan.

Scans and photos inside Notes are user files. There is no separate "clear attachments cache" that keeps the note intact.

Recently Deleted

In Notes, open the folder list.
Open Recently Deleted.
Recover notes you still want, or delete them to free space now.

Recently Deleted still uses space for up to 30 days. Emptying it is permanent.

Reinstall the app if storage is still high

If you already cleaned media and Notes still looks huge, a fresh install can clear leftover cache and temp files that are hard to reach by hand.

Confirm iCloud Notes has finished syncing. Export On My iPhone notes (scans and drawings included). Notes is a built-in app; offload is safer than treating it like a third-party reinstall.
Delete the app from your phone.
Restart your phone.
Install Notes again from the App Store or Google Play.
Sign in and restore from backup if the app offers it.

This often frees a lot of space. You may need to download some media again after restore.

What to do next

After Notes is lighter, check your photo library for duplicates and similar shots. That is what Dedupo is for.

More app guides: Free up app storage.