Dialog size in messages I own a 16gb iPhone and currently running out of space. After inspecting the storage manager I found out that the most storage has been consumed by messages. I tried to look for ways to see or order my dialogs biggest to smallest size by didn't find a way to do so. Is there a way I can do it on my phone or laptop or is the only option is blunt deleting all dialogs?
Please don't suggest deleting other apps
It is not possible to order messages by size on your phone. On your computer, it may be doable with a little Finder footwork. 

However, since it appears that you are running iOS 8, I suggest that you select to only keep messages for 30 days. If you open the Settings.app, navigate to Messages, then "Keep Messages" there are three options there with the shortest being 30 days. You may find this allows a good enough balance of your space. 

Also, the messages are automatically sorted by date, so you could manually delete the oldest threads which are automatically taking up space while not being used much. In addition, if there are any threads that you know (some use texts in a similar style to social media or iCloud photos) have many pictures, those should be the first to go.