Since Windows Phone syncs photos, videos, apps settings and SMS to the cloud (OneDrive), Did Microsoft provides any URL to read the synced SMSs online?
No, there is no way to view your Text Messages (SMS) online.
Windows Phone 8 does backup your text messages (SMS and MMS), if the feature is enabled, but the backup is now viewable - it's safely stored somewhere in the cloud.
If you transfer to a new WP8 device, that information can be restored to the new handset.
Backed up SMSes are displayed in Outlook.com categories, so:
- Go to http://outlook.com
- Click the cog -> Options -> Manage categories
- Tick/check "Show in folder pane" and "Filter" for "Unread" and "Contacts", for example.
- Go back to your inbox and click on the categories mentioned above to see relevant SMSes.