Residents of England and Wales will be able to compare local crime levels with other areas from tomorrow.
The Home Office is expanding its crime mapping website www.police.uk to allow people to compare crime levels for a certain borough or district.
The Compare Your Area tool is being launched a month before the voters elect the first police and crime commissioners.
The website, the Government's most popular online site in 2011, will also allow people to see how recorded crime rates have changed over the past three years, the Home Office said.
Policing minister Damian Green said: "The elections of police and crime commissioners will give the public a voice over how their neighbourhoods are policed and tools like Compare Your Area will ensure they have detailed information at their fingertips.
"The millions who have visited the website show the public's thirst for greater transparency across the whole criminal justice system.
"We want to build on trailblazing work in this area by publishing mug shots of convicted criminals on the site so that residents can see what steps were taken to crack down on criminals in their neighbourhoods."
The website will soon allow people to look at crime levels in smaller areas including villages and estates, and compare them with others and begin to feature mugshots of convicted criminals from the end of this month, the Home Office said.
West Yorkshire Police will start uploading people at the end of October, allowing civilians to see images of convicted criminals on the website along with a short summary of their crime and sentence.
It follows on from a pilot scheme in the force, known as "In the Dock". The Home Office is in discussions with 15 other forces about linking to the website.
Other tools which will be added to Police.uk in the coming months include email alerts which tell you when new updates are added or if an arrest on a certain street has led to a criminal sentence.
This year the site has already made available details of crimes which happen near hotspots such as nightclubs, parks and shopping areas.
More than 35 million people are eligible to cast ballots in the November 15 contests for the new commissioner posts, which will replace existing police authorities in 41 force areas across England and Wales.
The commissioners will have the power to set force budgets and priorities and even hire and fire chief constables.
But the elections have been dogged by concerns about low turnout at the polls.