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

Day 1:

• Start your day with a visit to the Kemeralti Bazaar, one of the oldest and largest bazaars in Turkey. You can find everything from spices to textiles to souvenirs here.
• After exploring the bazaar, head to Konak Square to see the iconic clock tower and take in the views of the Aegean Sea.
• Next, visit the Konak Yali Mosque, a beautiful Ottoman-era mosque located on the waterfront.
• End your day with a stroll along the Kordon, a popular promenade that offers stunning views of the sea and the city.

Day 2:

• Start your day with a visit to the ancient city of Ephesus, located about an hour's drive from Izmir. This well-preserved city was once a major center of trade and culture in the ancient world.
• After exploring Ephesus, head to the nearby town of Selcuk to visit the Temple of Artemis, one of the Seven Wonders of the Ancient World.
• End your day with a visit to the Sirince Village, a charming hillside village known for its wine and olive oil production.

Day 3:

• Start your day with a visit to the Izmir Archaeological Museum, which houses a vast collection of artifacts from the ancient city of Smyrna and other sites in the region.
• After the museum, head to the Alsancak neighborhood to explore its many cafes, restaurants, and shops.
• Next, visit the Asansor, a historic elevator that offers stunning views of the city and the sea.
• End your day with a visit to the Kadifekale, a hilltop fortress that offers panoramic views of the city.

Day 4:

• Start your day with a visit to the Izmir Wildlife Park, a large park that is home to a variety of animals, including lions, tigers, and bears.
• After the park, head to the nearby town of Urla to visit its many vineyards and wineries.
• Next, visit the Cesme Castle, a historic castle located on a hill overlooking the sea.
• End your day with a visit to the Cesme Marina, a popular spot for dining and shopping.

I hope this itinerary helps you plan your trip to Izmir!