You could easily spend a week in Osaka without feeling bored. But, for most people with limited time, a few days in Osaka would be good. For example, if you're coming to Japan for 10 days, it would make sense to spend a night and parts of two days in Osaka (and spend the rest of the time in Kyoto and Tokyo).

For a first-time visitor, two days is generally considered the perfect amount of time to experience the heart of Osaka without feeling rushed. This allows you to dedicate one day to the Osaka Bay Area (home to the world-class Kaiyukan Aquarium and Universal Studios Japan) and the Kita (North) district with its massive shopping complexes. The second day can be spent exploring the vibrant Minami (South) district, which includes the famous neon lights of Dotonbori, the "kitchen of Osaka" at Kuromon Market, and the historic Shinsekai area. If you are using Osaka as a regional hub to visit nearby Himeji, Nara, or Kobe, you should extend your stay to four or five days. Osaka is often called "Japan's Kitchen," so even if you've seen the major sights, staying an extra night just to explore the izakayas (Japanese pubs) and street food stalls of Tennoji or Namba is a highlight for many travelers. However, for a focused city tour, 48 hours is the "sweet spot" to capture the city's energetic and unpretentious spirit.