Shearer joined the Alex last summer from Rotherham on a two-year deal and the remaining 12 months of that agreement have been waived.
The 34-year-old held a player/coach role at Gresty Road but has expressed a desire to concentrate on playing again after finding first-team opportunities limited at the League One club, for whom he made just three appearances last season.
He spent the second half of last term on loan at Burton but played only once for the promotion-winning Brewers.
A statement on Crewe’s official club website said: “Everyone at the club would like to wish Scott all the best for his future.
“Following Scott’s departure, Crewe will now be looking to add another goalkeeper to their ranks to challenge Ben Garratt and a new coaching coach.”