Here are the NJ guidelines:

Pre-Registration: 17-year-olds who will be 18 by the next general election can pre-register to vote. On your 18th birthday, your voter registration application will be fully processed. Same Day Registration: New Jersey does not offer the opportunity to register to vote on Election Day. Automatic Voter Registration: New Jersey does not automatically register eligible citizens to vote when they go to a government agency, like the DMV. If You've Moved: New Jersey requires registrants to live in the state for at least 30 days before registering to vote. Documentation Requirements: When submitting a voter registration application, no additional documents are required for your registration to be processed. The state confirms your citizenship and eligibility through the information provided on your registration form, such as your state-issued license/ID number or the last 4 digits of your SSN. Voting Rights Restoration: In New Jersey, the voting rights of convicted persons are automatically restored upon completion of one's sentence. Returning citizens must re-register to vote after their rights are restored. Interstate Voter Rolls Accuracy & Maintenance: New Jersey does not participate in any coordinated effort with other states to compare voter rolls for maintenance purposes.