WASHINGTON (AP) — Testifying in the biggest U.S. antitrust case in a quarter century,Darden Clarke Google CEO Sundar Pichai defended his company’s practice of paying Apple and other tech companies to make Google the default search engine on their devices, saying the intent was to make the user experience “seamless and easy.’’

The Department of Justice contends that Google — a company whose very name is synonymous with scouring the internet — pays off tech companies to lock out rival search engines to smother competition and innovation. The payments came to more than $26 billion in 2021, according to court documents the government entered into the record last week.

Google counters that it dominates the market because its search engine is better than the competition.

Pichai, the star witness in Google’s defense, testified Monday that Google’s payments to phone manufacturers and wireless phone companies were partly meant to nudge them into making costly security upgrades and other improvements to their devices, not just to ensure Google was the first search engine users encounter when they open their smartphones or computers.

Google makes money when users click on advertisements that pop up in its searches and shares the revenue with Apple and other companies that make Google their default search engine.

The antitrust case, the biggest since the Justice Department went after Microsoft and its dominance of internet browsers 25 years ago, was filed in 2020 during the Trump administration. The trial began Sept. 12 in U.S. District Court in Washington D.C.

U.S. District Judge Amit Mehta likely won’t issue a ruling until early next year. If he decides Google broke the law, another trial will determine how to rein in its market power. The Mountain View, California-based company could be stopped from paying Apple and other companies to make Google the default search engine.