Yes, several websites let you design a garden in your browser, from simple 2D planners to AI tools that work from a photo of your yard. Gardena's My Garden is a free drag-and-drop planner that handles beds, paths, and plant spacing. SketchUp's free web version gives you precise 3D modeling, though expect a learning curve measured in hours, not minutes.
AI photo tools are the newer option: upload a picture of your garden, pick a style like cottage or modern, and get realistic redesign concepts of your actual space in under a minute. Most are paid.
If you've already tried prompting a chatbot for garden images, our ChatGPT landscape design page shows how that stacks up against a tool built for yard photos.