Alibaba is the world's fifth largest online company in 2021.

1. Amazon

Amazon was launched in 1995 as an online bookstore and has since diversified to become the largest internet-based retailer in the United States.

In 2019, revenue was $280.52 billion. As of June 30, 2020, the market value was $1.38 trillion.

2. Alphabet Inc.

Alphabet Inc. is the parent company of internet search giant Google. Google is a global leader in search, contextual advertising, and other online products. Google, listed on NASDAQ, had a market value of $964.51 billion on June 30, 2020.

In 2019, total revenue was $161.86 billion.7

3. Facebook

Facebook, listed on NASDAQ, is the most popular social networking site in the world.

In October 2014, it acquired WhatsApp for a whopping $19 billion and made many other relatively small acquisitions. Facebook's total revenue in 2019 was $70.7 billion.

On June 30, 2020, the market value was $647.15 billion.

4. Tencent Holdings

Tencent Holdings Limited (Tencent Holdings) is a household name in Asia, known for its applications, online games, advertising and messaging services such as WeChat.

In 2019, Tencent Holdings had revenue of $56.59 billion and a market value of $614.68 billion on June 30, 2020.

5. Alibaba

New York Stock Exchange-listed Alibaba made headlines in 2014 when its initial public offering became the world's largest IPO ever. Alibaba is a Chinese e-commerce giant with a market value of $581.20 billion as of June 30, 2020.

In 2019, revenue was $56.15 billion.