Genshin Impact Run and Dash Speed Comparison
Comparison of movement methods across all character types.
Tall males are fastest across the board.
Relative speed doesn't change based on movement method. Order of fastest to slowest: Tall Male, Tall Female, Short Male, Short Female, Loli
Sprint is least efficient method of movement, expending the most stamina while being barely faster than stamina neutral dash method (except for Tall Males who are actually faster using stamina neutral).
Double Dash is indeed the fastest way to move, but isn't particularly stamina efficient.
Thanks to the absurd dash of Tall Males, the stamina neutral dash Tall Male is faster than Double Dash Loli and Double Dash Short Female. Which means Tall Males don't need to spend any stamina to be faster than the fastest a Loli or Short Female can move.