Amazon (AMZN -1.38%) reported powerful first-quarter 2021 results after the market close on Thursday.  Shares of the e-commerce and cloud-computing leader rose 2.4% in Thursday's after-hours trading session.

We can probably attribute the market's initial reaction to both revenue and earnings sailing by the Wall Street consensus estimates, as well as second-quarter revenue guidance coming in higher than analysts had been expecting. Here's an overview of the technology-giant's quarter, along with its guidance.

A man holding an Amazon box opening a door with his daughter.

Image source: Amazon.com.

1. Revenue surged 44%

Amazon's net quarterly sales surged 44% year over year to $108.5 billion, beating the $104.5 billion Wall Street had expected. The company also comfortably surpassed its guidance range of $100 billion to $106 billion. Excluding the boost from foreign-currency exchange, revenue jumped 41%.

For context, in the first, second, third, and fourth quarters of 2020, Amazon's year-over-year revenue growth was 26%, 40%, 37%, and 44%, respectively. Here's how revenue broke down by segment:

Segment

Q1 2021 Revenue 

Change (YOY)

North America

$64.4 billion

40%

International

$30.6 billion

60%

Amazon Web Services (AWS)

$13.5 billion

32%

Total

$108.5 billion

44%

Data source: Amazon. YOY = year over year. 

Amazon's e-commerce businesses around the world continued to get a boost from the COVID-19 pandemic. Many consumers are still avoiding brick-and-mortar stores as much as possible. 

For context, last quarter (the holiday quarter), year-over-year revenue growth in the company's North America, international, and AWS segments was 40%, 57%, and 28%, respectively.

2. Operating income soared 123%

Operating income increased 123% year over year to $8.9 billion, which crushed Amazon's guidance of $3 billion to $6.5 billion.  

Segment

Q1 2021 Operating Income

Change (YOY)

North America

$3.5 billion

163%

International

$1.3 billion

N/A. Improved from a loss of $398 million in the year-ago period.

AWS

$4.2 billion

35%

Total

$8.9 billion

123%

Data source: Amazon. YOY = year over year.

3. EPS more than tripled

Net income rocketed 224% year over year to $8.1 billion. This translated to earnings per share (EPS) growing 215% to $15.79. Wall Street was only expecting EPS of $9.54. 

4. Operating cash flow jumped 69%

Operating cash flow increased 69% year over year to $67.2 billion for the trailing 12 months. Free cash flow rose 9% over the same period to $26.4 billion.

5. Second-quarter 2021 revenue is expected to grow 24% to 30%

For Q2, Amazon guided for net sales in the range of $110 billion to $116 billion, which would equate to year-over-year growth of 24% to 30%. This outlook assumes Prime Day will occur in the second quarter, rather than in its traditional spot in the third quarter. (Last year, it was held in the fourth quarter due to the pandemic.) The company's entire guidance range exceeds Wall Street's consensus estimate of $108.7 billion. 

Amazon (which doesn't provide earnings guidance) also expects that its operating income will be between $4.5 billion and $8 billion, compared with $5.8 billion in the year-ago period. That range means management thinks operating income could decline by as much as 22% or rise by as much as 38%. This outlook includes about $1.5 billion in costs related to COVID-19.

For some context, going into the report, Wall Street had been modeling for Q2 EPS growth of 5% year over year. 

In short, Amazon turned in a super quarter -- again -- and its outlook remains bright.