One more synonym could be 'it's a prolonged tale'. The word 'prolonged' indicates that something is made longer than normal or expected, which is exactly what 'it's a long story' implies. For instance, when you start to tell a story that has a lot of background information or events, you can say 'it's a prolonged tale' to give the listener an idea that it will take some time to finish the story.
It could be 'it's a protracted account'.
There are several synonyms, like 'it's a complex matter' or 'it's a convoluted tale'.
Some synonyms could be 'a lengthy tale' or 'an extended narrative'.
Epic, saga, tale. These words can be used in place of 'long story' in many cases. For example, instead of saying 'Here is a long story', you could say 'Here is an epic' or 'Here is a saga'.
A long tale. For example, 'The Odyssey' by Homer is a long tale full of adventures.
A long tale. For example, when we talk about the legend of King Arthur, it is like a long tale filled with adventures, romances and heroic deeds.
You can say 'He told an elaborate account of his adventures.'
A drawn - out story. For example, a long - winded fable that goes on and on with many details and moral lessons.
Well, 'an engaging tale' or 'a captivating narrative' could be synonyms for a good story.
Virtuous. For example, a character who is always honest and kind can be described as virtuous.