Thank you, Balaji, and thanks for everyone joining us today. Since our last earnings call, the world has made considerable progress in the fight against COVID. While there’s still a lot of work to do, we’re cautiously optimistic that this progress will continue and effect, accelerate over the next quarters. However, longer recovery takes Uber’s business remains well-positioned.
Despite renewed lockdowns in Q4, we ended the year with total company gross bookings nearly flat year on year in December with gross bookings turning positive in January. Disciplined execution and increased scale in our delivery business allowed us to improve adjusted EBITDA by $161 million year on year in Q4. This quarter marks the completion of a series of portfolio actions that began in Q2, with the goal of focusing the company on its two massive core opportunities of mobility and delivery.
We executed 17 transactions in 2020, including acquisitions that increase our run rate gross bookings by over $6 billion and divestitures of non-core operations that, combined with other cost optimization actions, reduced our annualized EBITDA losses by over $1 billion.
These transactions, coupled with disciplined operational execution and continued product innovation have put us on a stronger and more focused foundation heading into 2020. As such, we have increased confidence in our ability to reach breakeven this year while continuing to invest in long-term initiatives close to our core. Looking ahead, our strategic priority in 2021 is to continue to harness the power that our platform that is multiple and growing product offerings can uniquely provide. Wherever you need to go, whatever you need to get, Uber can help.
We believe our highly engaged consumer base on delivery will drive stronger mobility growth as cities reopen. On the flip side, we expect Mobility to become an increasingly powerful acquisition channel for our delivery business. For instance, our redesigned Uber super app already generated more than 10% of first-time eaters in Q4. We plan to accelerate cross-platform usage through a renewed focus on our Uber Pass and Eat Pass membership programs.
We believe these will only become more valuable as we add new benefits and verticals like pharmacy and alcohol. Memberships ramped up significantly in Q4 with over 5 million members across 16 countries, and we have aggressive global expansion plans in 2021. Now I’ll dive into each of the core segments. First, mobility, which continues to be affected by lockdowns around the world.
Mobility GBS improved modestly in the fourth quarter, up 15% from Q3 levels but still down 47% year on year. In January, gross bookings were down 47% year on year, declining 10% month-on-month post-elevator holiday activity in December. We’re seeing extremely encouraging trends in APAC and Latin America with growth bookings in those two regions down only 25% to 30% in January. Two of our largest markets, Brazil and Australia, were down only 10% to 20% in January, while Taiwan grew 16% year on year.
The recovery in these markets demonstrates consumers’ pent-up desire start moving again while Uber is continuing to gain share versus other modes of transportation. Over the next six months, we’ll begin to prepare our business to go from preservation mode to reposition. This means investing in new Mobility products such as either reserve, rentals, transit, taxis, and motorbikes and rolling out new segmented offerings like Uber Comfort. We will focus on reengaging riders for their second first trips and reengaging drivers to meet ramping demand.
If we do these things right, and the public health situation improves as expected, we’re bullish that we can deliver strong growth and expanding margins in the second half of the year.