Prosus NV said it struck a $1.8 billion deal to acquire Stack Overflow, an online community for software developers, in a bet on growing demand for online tech learning.

Based in New York, closely held Stack Overflow operates a question-and-answer website used by software developers and other types of workers such as financial professionals and marketers who increasingly need coding skills. It attracts more than 100 million visitors monthly, the company says.

Prosus, one of Europe’s most valuable tech companies, is best known as the largest shareholder in Chinese internet and videogaming giant Tencent Holdings Ltd. Listed in Amsterdam, Prosus signaled its appetite for deal making when it sold a small portion of its equity stake in Tencent in April for $14.6 billion. The Stack Overflow deal ranks among Prosus’ biggest acquisitions.

Prosus invests globally across a range of online platforms focused on areas such as food delivery, classifieds and fintech. It also maintains a more than $200 billion holding in Tencent. Prosus’ parent company, Naspers Ltd. , acquired the Tencent stake in 2001 for $34 million.

The Stack Overflow deal is Prosus’ first outright acquisition in the educational tech space. Prosus already owns stakes in two educational tech companies—Udemy and Codecademy—servicing companies. It is set to make an investment in Skillsoft, a publisher of training software used by businesses as part of that firm’s plan to merge with special-purpose acquisition company Churchill Capital Corp II and list in New York.

Prosus is betting that companies will continue to build out technology to support remote working and online training long after the Covid-19 pandemic recedes.

“The pandemic brought this sector to the forefront and what we are going to see in the coming months is a wave of consolidation,” pushing the company to make acquisitions or risk losing out on targets, said Larry Illg, who oversees educational tech investments at Prosus.

Prosus is acquiring Stack Overflow from the company’s founding venture-capital investors, including Union Square Ventures; Index Ventures; Andreessen Horowitz; Bezos Expeditions, an investment vehicle of Amazon.com Inc. founder Jeff Bezos ; Spark Capital; Silver Lake and GIC, the Singaporean sovereign-wealth fund.

Stack Overflow’s website is free to access. It generates advertising revenue from companies promoting technology products and wooing prospective tech employees.

The company also offers a subscription software-as-a-service product called Stack Overflow for Teams to businesses that want access to a private version of the public platform for their employees to collaborate. That product’s features include the ability to integrate with other tools such as GitHub, a coding-collaboration site that Microsoft Corp. acquired for $7.5 billion in 2018.

Siemens AG , Chevron Corp. , Microsoft and Liberty Mutual Group are among the businesses using Stack Overflow for Teams, said Prashanth Chandrasekar, the company’s chief executive.

About 85% of the businesses that use Stack Overflow’s Teams product are based in the U.S. Prosus aims to expand that platform geographically including in developing markets like India, where it has already had success expanding online platforms such as its PayU payments company.

“The ability to replicate that success internationally is a huge focus” for the deal, Mr. Chandrasekar said.

Stack Overflow will also gain access to the business customers of Prosus’ other portfolio companies in the educational tech sector, the companies said.

Write to Ben Dummett at ben.dummett@wsj.com

Corrections & Amplifications
The Stack Overflow deal ranks among Prosus’ biggest acquisitions. An earlier version of this article incorrectly said the deal was Prosus’ biggest acquisition. (Corrected on June 2)