Citizens of Brunei, Canada, Hong Kong, Japan, Malaysia, Singapore, South Korea and the U.S. can apply for an Electronic Travel Authority (ETA) visa with a valid passport. An ETA visa is an electronic visa for which the holder doesn't have to apply at a consulate or embassy; an eligible individual can apply online and be approved in 30 seconds or can submit his information through a travel agent or airline. ETA visas are valid for up to three months and cannot be extended.
eVisitor visas are electronic visas granted to citizens of European countries (for a full list, visit http://www.immi.gov.au/visitors/tourist/evisitor/eligibility.htm) for short vacations or business trips. To get an eVisitor visa, apply online by entering your passport information at least two weeks before traveling. The visas are valid for twelve months, allowing visits of up to three months during that period.
If you are a citizen of any other country---or someone with an ETA- or eVisitor-eligible passport who wishes to stay in Australia for longer than three months, you must apply for a tourist visa. Fill out an application and submit it, a passport and supporting documents to an Australian consulate or embassy. The visa is valid for three, six or 12 months.
