Amazon’s site crashed on Monday at about 3 p.m. — just as its highly anticipated Prime Day kicked off.

Shoppers rushing to the site to get deeply discounted gadgets and gizmos instead found a parade of pooches — photos of dogs that served as Amazon’s default tech-problem landing page.

“I’m candidly shocked that they’re not prepared for the traffic,” Forrester analyst Sucharita Kodali told Bloomberg. “Unless this is way beyond their wildest expectations, it’s just odd.”

The 36-hour-long Prime Day event was expected to ring up roughly $3.4 billion in sales.

The Web site crash meant that many shoppers hoping to snag a 28 percent discount on a Toshiba 50-inch Smart television, equipped with Amazon’s Fire TV technology — normally priced at $399.99 — were left anxiously refreshing their browsers only to be greeted by the playful puppies.

Third-party sellers also found themselves burned by the glitch.

“They hyped the biggest sales event for third-party sellers, and the system is broken. I can’t enter new inventory that I invested in specifically for Prime Day,” one frustrated Amazon Prime seller told The Post.

While some users were blocked, others shopped without issue.

More items were ordered in the first hour of Prime Day this year than last year, Amazon said in a statement.

By 3:40 p.m. in New York, Amazon seemed to be back for some users.

Amazon noted the problems and said it was “working to resolve this issue quickly.”

Amazon Prime Day is a special event whereby Prime members — those who have paid the $119 annual fee for free two-day shipping and other perks — can get extreme discounts.

Amazon shares, which rose 1.6 percent at 2:17 p.m., closed up 0.5 percent, or $9.46, at $1,822.49. The shares slipped 1.1 percent in after-hours trades.