Another 500 police officers will be put on local policing duties.
The changes are due to come in to effect on September 1.
Essex Chief Constable Stephen Kavanagh said: "I believe the public of Essex want policing delivered locally.
"For me it is about locally based, locally accountable, locally led officers, police community support officers and staff delivering across a range of response, investigation and engagement responsibilities."
Mr Kavanagh said the number of officers in some specialist functions such as firearms, roads policing and public order will be reduced so that more can carry out local policing duties.
This will include moving about 400 centrally controlled response officers.
He said careful consideration has been given to reducing the numbers in specialist functions, adding: "The force retains the right level of resourcing in these important specialist areas.
"I am committed to policing our road network and the essential task of working with partner agencies and drivers to improve safety.
"We also maintain the capability to rapidly respond to incidents involving firearms as well as continuing to meet our public order commitments both in Essex and across the region."
Essex Police is also launching a recruitment drive for new constables.