Here's an ideal itinerary for 4 days in Amsterdam:

Day 1:

• Start your day with a visit to the Van Gogh Museum, which houses the largest collection of Van Gogh's paintings and drawings in the world.
• After the museum, take a stroll through the Vondelpark, Amsterdam's largest park, and enjoy a picnic or a coffee at one of the park's cafes.
• In the afternoon, head to the Jordaan neighborhood, known for its charming streets, trendy boutiques, and cozy cafes. Take a canal boat tour to see the city from a different perspective.
• End your day with a visit to the Anne Frank House, where you can learn about the life of Anne Frank and her family during World War II.

Day 2:

• Start your day with a visit to the Rijksmuseum, which houses a vast collection of Dutch art and history, including works by Rembrandt and Vermeer.
• After the museum, head to the Albert Cuyp Market, one of the largest outdoor markets in Europe, where you can find everything from fresh produce to clothing and souvenirs.
• In the afternoon, visit the Heineken Experience, where you can learn about the history of Heineken beer and enjoy a tasting.
• End your day with a visit to the Red Light District, where you can see the famous red-lit windows and learn about the history and culture of the area.

Day 3:

• Start your day with a visit to the Amsterdam Museum, where you can learn about the history and culture of Amsterdam.
• After the museum, head to the Negen Straatjes (Nine Streets) neighborhood, known for its boutique shops, vintage stores, and cozy cafes.
• In the afternoon, visit the Rembrandt House Museum, where you can see the home and studio of the famous Dutch painter.
• End your day with a visit to the Dam Square, the heart of Amsterdam, where you can see the Royal Palace and the National Monument.

Day 4:

• Start your day with a visit to the Artis Royal Zoo, one of the oldest zoos in Europe, where you can see a variety of animals and learn about conservation efforts.
• After the zoo, head to the Plantage neighborhood, known for its beautiful parks and gardens, including the Hortus Botanicus, one of the oldest botanical gardens in the world.
• In the afternoon, visit the Museumplein, a public square that houses several museums, including the Stedelijk Museum of modern art and the Moco Museum of contemporary art.
• End your day with a visit to the Westergasfabriek, a former gasworks that has been transformed into a cultural center with restaurants, bars, and events.