All in all—
1. taking everything into consideration.
- All in all, they do their best to portray something original.
2. (of a person or thing ) of supreme importance to somebody.
- This adventurer made love to the girl that was all in all to me.
In all—in total number.
- I stayed for three days in all, and throughout those three days I was sitting in their wonderful library.
Note: The expression does not correlate in meaning with the phrase at all—under any circumstances.
- If that is so, why write at all?