2012 Olympics tickets go on sale
Some 6.6 million tickets are available to buy over a six-week period, in which every application will be treated equally, say the organisers.
Prices range from £20 to £2012 and oversubscribed events will be decided by a ballot.
On Monday a giant clock counting down the days until the start of the Games was unveiled in Trafalgar Square.
BBC sports editor David Bond said the ticket sale launch would be the first real test of public appetite for the event.
Organisers said they were confident they had done everything they could to avoid the website crashing as people log on for the first time to buy tickets.
The main factor is the establishment of a 42-day sales process which means each application between now and 26 April will be treated in exactly the same way.
People can also apply for tickets using a paper form, which is included in the official ticketing guide.
Half a billion pounds is forecast to be raised from ticket sales.
Several events will be free, such as the marathon, and 2.5 million tickets will be available for £20 and under. Others start at between £30 and £50.
Children under 17 will be able to "pay-your-age" to see some of the early heats, while the over-60s can watch for £16.
In total, there are 8.8 million tickets but some 1.2 million are reserved for various government bodies, the London mayor, sponsors and athletes; Kazinform cits BBC News.
Read more at www.bbc.co.uk