A staff memo by Chief Executive Sundar Pichai was shared with Reuters.
In it he said the company had rapidly expanded headcount in recent years.
But that was for what he called a 'different economic reality than the one we face today'.
Alphabet's job losses affect teams across the company, including recruiting, engineering and more.
The layoffs are global, and will impact U.S. staff straight away.
But the process will take longer in other countries due to local employment laws and practices.
The cuts follow a similar move made by rival firm Microsoft.
Earlier this week, it said it would lay off 10,000 workers.
The update comes at a moment of economic uncertainty and technological potential.
Both Google and Microsoft have invested heavily in an area of software known as generative artificial intelligence.
Microsoft said it continued to ramp up spending in that area.
