Google has launched a new feature that lets users explore how places around the world have changed since it launched Street View seven years ago.

"This will let you go back in time up to 2007," said Vinay Shet, product manager for Street View. "It paints a picture of how the world has been. It's a mirror of the world across time."

The feature is rolling out around the world over two days. As of 10:30 a.m. ET Wednesday, it was live in the U.S., but had not yet rolled out in Canada.

Google Canada spokesman Aaron Brindle said he would alert CBC News when Canadian users are able to try it out.

Brindle suggested that one interesting thing for Canadian users to check out is how Toronto's Lake Shore Boulevard has changed during the condo boom over the past few years.

Google Street View

Street View users can watch the construction of buildings like this one in Singapore. (Google)

Shet suggested using the new feature to see:

  • The construction of landmarks such as the 2014 World Cup Stadium in Fortelaza, Brazil.
  • The destruction wrought by natural disasters such as the 2011 earthquake and tsunami on places like Onagawa, Japan, and how they have been rebuilt.
  • How different cities such as Kyoto, Japan, look when covered in spring cherry blossoms and in the summer.

"It's also an opportunity to see how humanity has evolved culturally," said Shet, pointing out the evolution of technology from flip phones to smartphones in ads in New York's Times Square during an online video demo.

The availability of the new feature is indicated by a little clock in the upper left of a given Street View scene. A slider allows you to toggle among views from different times. Google has also dressed up its yellow Google Street View man icon as Doc Brown, the time machine inventor from the movie Back to the Future, for the launch.

The new feature will allow you to see some previously unpublished Street View images captured over the years, such as night shots of Times Square. Their quality wasn't high enough to allow them to be the main images on Street View, but Shet said they now can be used to add context.

The feature also preserves access to Street View images that are meaningful to some users. Shet gave the example of a man whose parents died some time after having been captured in Street View imagery. He was afraid the image would be replaced by a newer view of the street.

Japan Earthquake

Some images show cities such as before and after natural disasters such as the massive 2011 earthquake and tsunami in Japan. (Google)

Some Street View pictures posted through the years have also upset people who were captured in activities or visiting places that they wanted to keep private. Google now blurs the images of people who contact the company asking to be shielded from Street View. Masking will be available on the older photos too, Shet said, even if it's just because a person didn't like the way he or she looked a few years ago.

PIctures to be added to digital time capsules

On average, in most places, only one image from the past will be available in addition to the most recent Street View image.

However, many past images will be available in major city centres because Google's Street View cars tended to visit those areas more frequently.

Google Inc. intends to keep adding pictures to the digital time capsules as its photo-taking cars continue to cruise the same streets gathering updates.

Like everything else on Google's map, the time-tripping option is free. Google makes money off its maps from advertising, so the Mountain View, Calif., company is constantly coming up with new attractions to keep people coming back.

Google Street View is used by a billion people each month and currently spans 55 countries.

The look-back feature will be available in all but three of those countries: Germany and Switzerland, where government regulations restrict Google's use of the past images, and South Africa, where technical problems have slowed the feature's rollout.

With files from the Associated Press