There is no way to experience the full circuit without climbing.
Entrances take you up to the wall level, and the route itself rises and falls around towers and fortifications. The exact effort depends on your starting point and how much of the circuit you complete.
Minčeta is the most obvious extra climb.
The highest point of the fortifications is Minčeta Tower. Reaching its upper viewpoints adds more climbing on top of the main circuit, so it is reasonable to skip optional tower climbs if the full walk is already enough.
Accessibility needs should be checked before buying.
The official FAQ says the sites are difficult to access for people with disabilities. If step-free access is essential, treat that as a reason to verify conditions directly with the operator rather than relying on a generic travel blog.
Heat magnifies the physical effort.
Steps that feel fine in mild weather can feel very different on exposed summer stone. Shoes with good grip, water and a cooler time of day make the route more manageable for many visitors.
Quick answers
Are Dubrovnik City Walls wheelchair accessible?
The official operator states that its heritage sites are difficult to access for people with disabilities. The historic circuit contains extensive stairs and should not be treated as step-free.
Are there many stairs?
Yes. There are repeated climbs and descents throughout the route, with additional steps at towers such as Minčeta.
Can I do only part of the Walls?
There are multiple entrances/exits, but the practical options can depend on current visitor routing. Ask staff on the day if you are planning a shortened visit.
References: Official City Walls FAQ · Dubrovnik Tourist Board: City Walls and Fortresses