The website has been created with images of items found during the construction of the Elizabeth Line, which include a 8,000-year-old flint scraper tool and a Tudor bowling ball.
Archaeologists have uncovered more than 10,000 artefacts during the work.
The website features items from an exhibition about the project at the Museum of London Docklands.
The online exhibition of Tunnel: The Archaeology of Crossrail takes visitors on a journey along the route of the new railway, with photographs and footage captured during archaeological excavations.
The items reveal the stories of Londoners, from Mesolithic tool makers to those affected by the Great Plague of 1665.
Jay Carver, Crossrail's lead archaeologist, said: "The Crossrail project has given archaeologists a unique opportunity to look at important areas of London that have been tantalisingly out of reach for centuries.
"This fantastic immersive website uses the best of the photo and video content captured during the excavations to let people explore over 8,000 years of the capital's hidden history."
The new Elizabeth line is due to open in 2018.
A new virtual exhibition of artefacts unearthed during the Crossrail project has been launched.