Honestly, it depends entirely on the type of bench and how you install it. Outdoor benches are not automatically permanent just because they sit outside. Some are incredibly easy to move, while others are designed to stay put for decades. Let me break it down in a practical way.
First, think about weight. A lightweight aluminum or plastic bench that you simply unfold or set on the grass is obviously easy to move. You can pick it up by yourself and carry it to a new spot in under a minute. These are the kind you often see on patios, decks, or by a fire pit. They're portable by design, not permanent at all.
On the other hand, a heavy cast iron or solid teak bench might not be bolted down, but moving it could require two or three people. It's not technically permanent, but you won't casually relocate it every weekend. The weight alone makes it feel like a fixture.
Now, installation makes the biggest difference. If the bench is set on a flat surface with no anchors, like just placed on concrete or grass, it's easy to move whenever you want. But if it's bolted into a concrete pad, set into the ground with concrete footings, or mounted permanently to a wall or deck, then no, it's not moving without serious work. Bolted benches are meant to prevent theft and shifting, especially in public parks or commercial spaces.
There's also the middle ground: benches with anchor kits. Some manufacturers give you the option to use ground spikes or brackets for semi-permanent stability. You can remove the bolts and move the bench, but you'll leave behind small holes or brackets. That's a good compromise if you want some flexibility without drilling into a slab.
So to answer your question directly: if you choose a lightweight bench and don't anchor it, it's very easy to move. If you choose a heavy bench and bolt it down or set it in concrete, it's effectively permanent. The bench itself doesn't decide that—you do at installation time. Just think about whether you want the freedom to rearrange your outdoor space or the security of a bench that won't wander off or shift under weight.