Yes, you can use an urban planter box indoors near a bright window, but whether it is a good idea depends on the box, the window, and how much maintenance you are willing to do. Many urban planter boxes are built for balconies, patios, or rooftops, not living rooms. They are often heavy, have open drainage holes, and hold a large volume of wet soil. Indoors, those features can create water damage, humidity problems, and pest issues if they are not managed well. Near a bright window, the biggest benefit is light: herbs, lettuce, compact peppers, and other small edible plants can grow reasonably well. The window also provides warmth, but in summer it can become too hot, especially if the planter sits directly against glass. Leaves may scorch, soil may dry unevenly, and condensation may form between the planter and the window frame.
The first thing to check is drainage. A planter box without drainage is risky for most plants because excess water collects at the bottom and roots rot. A planter with drainage is better for the plants, but indoors it needs a waterproof tray, liner, or a cachepot system so water does not ruin floors or windowsills. If the box is too large to move, use a heavy-duty saucer and check it after every watering. For edible plants, choose a food-safe liner and avoid unknown treated wood. Weight is another issue: wet potting mix is much heavier than dry mix, and a long planter box can put stress on a windowsill or floor. Use a sturdy stand or place it on a stable floor area rather than a narrow sill.
Moisture and airflow matter as much as light. Indoor air is often still, so a dense planter can stay damp and encourage fungus gnats, mold, or mildew. Water carefully, let the top layer of soil dry as appropriate for the plants, and keep a small fan or natural air movement nearby. Bright windows can also overheat plants in summer and become cold drafts in winter. Watch the leaves for scorching, leggy growth, or yellowing. Choose compact, light-loving plants that suit indoor conditions, and use a lightweight, free-draining potting mix rather than garden soil. If the window does not provide enough light during darker months, add a small grow light.
In short, an urban planter box indoors near a bright window is not a bad idea by itself, but an outdoor planter is not automatically indoor-ready. It works best when you use a waterproof, well-draining setup, protect the floor and sill, choose suitable plants, and monitor heat, drafts, moisture, and pests. If you cannot control drainage or weight, use the planter box as a decorative outer container and keep the actual plant in a smaller pot with a saucer inside. That gives you the urban planter look without turning your window area into a muddy, humid problem.