SpikeUI is a visual user interface designer and application builder for desktop and web platforms. It enables users to create application interfaces through a visual editor and export the results to HTML, CSS, and JavaScript, or directly to a native Windows executable. The software is offered as a one-time purchase without subscriptions or hidden fees, and applications created with it operate offline without external dependencies. The editor follows a WYSIWYG approach, so the design shown on the canvas matches the exported result. It includes a library of controls such as buttons, inputs, and selectors, along with a visual hierarchy of interface elements. Users can manage themes through a visual color editor and adjust typography, spacing, borders, shadows, gradients, dimensions, padding, margins, and scale. While the primary workflow is visual, users have full access to the generated code for deeper customization. A built-in AI assistant can design, wire, and refine components on the canvas based on a user description, with a plan approval step before changes are applied. The assistant can use accounts from compatible AI providers or private and free local models. SpikeUI supports multiple export targets: a Windows executable (.exe), a PureBasic module (.pbi), a single-file web application, or separate HTML, CSS, JavaScript, and asset files. Exported applications run on Windows and in modern browsers. The output is self-contained, with no external libraries at runtime, no CDN, and no auxiliary frameworks. Multi-language support is available in the editor, the documentation, and relevant parts of the exported output. Typical use cases include building Windows desktop applications and web applications from visual designs, prototyping interfaces, and producing offline-capable software without runtime dependencies.