Netflix Inc. raised prices for all of its subscription plans, a move that fortifies the streaming-video giant’s aggressive spending on content in the face of stepped-up competition.

Netflix, which last raised its prices in late 2017, will increase the cost of its most popular plan by 18% to $13 a month, from $11. That plan allows users to stream on two screens at the same time. The most basic plan, which allows a single stream, will go up one dollar, or 13%, to $9 a month.

Raising prices will help Netflix swallow higher content costs as the streaming TV wars intensify. An array of companies—from Amazon.com Inc. and Hulu to new entrants like AT&T Inc. and Walt Disney Co.—are seeking to secure the premier movie and TV rights that will attract subscribers. Netflix is already a heavy spender, and those outlays will likely rise further amid the competition.

The company’s shares rose 6.5% to $354.64 on Tuesday. Netflix has increased its revenue at a rapid pace over the past several years, but it hasn’t generated huge profits, and investors have been watching to see if the company would turn up the lever on pricing.

The new rates will go into effect immediately for new customers in the U.S. and be applied to the accounts of existing U.S. customers in the next few months, according to a person familiar with the plans. The increases will also apply to countries in Latin America and the Caribbean where Netflix bills in U.S. currency.