What each option actually is

Pee pads are absorbent, often scented, disposable (or washable) mats placed in a fixed indoor spot. Indoor grass is a tray of real or artificial turf, usually with a drainage layer underneath, designed to feel and smell more like the ground a dog would use outside. Both aim to give a dog an approved indoor toileting spot, but they teach slightly different habits.

Where pee pads make sense

Pee pads work well for very young puppies who can't yet hold their bladder long enough to always make it outside, for apartment dwellers on a high floor where fast outdoor access isn't realistic, and for owners managing a long workday with no one able to let the dog out at midday. They're also useful short term after surgery or during illness when outdoor trips aren't practical.

Where indoor grass has the edge

Indoor grass is generally the better long-term choice for a dog that will eventually be expected to toilet on grass outside, because the surface and smell already match what they'll transition to. It also tends to feel less like "indoors is a bathroom" and more like a designated toileting zone with its own texture, closer to a genuine outdoor cue. For small breed adult dogs who will always primarily toilet indoors (common in some apartment setups), indoor grass with proper drainage and cleaning holds up better over time than pads.

The downside of both

Any approved indoor spot can slow down full outdoor training if a dog decides the indoor option is just easier, particularly in bad weather. If your long-term goal is exclusively outdoor toileting, be deliberate: move the indoor spot progressively closer to the door and eventually outside over several weeks, rather than leaving it in a fixed spot indefinitely once the dog is capable of holding it.

Making the choice

If you need an indoor solution only temporarily, a young puppy, a recovery period, bad weather, pee pads are the simpler, cheaper option. If you want a setup that either transitions smoothly to full outdoor training or serves as a permanent indoor solution for a small dog, indoor grass is worth the extra cost and maintenance. Whichever you choose, keep the spot consistent, clean it thoroughly with an enzymatic cleaner after each use so scent doesn't build up elsewhere, and reward calmly when your dog uses it correctly.