There is no single app called Lightning Platform Builder to open. To start building declaratively, you open a specific builder from Setup. The steps below use Lightning App Builder, the most common entry point, to create a new Lightning page. The same Setup-first pattern works for Object Manager, Flow Builder, and Schema Builder.
- Open the builder from Setup
Click the gear icon and choose Setup. In the Quick Find box, type Lightning App Builder and select it. To reach a different builder, type its name instead, such as Flows or Schema Builder. Every declarative builder is reachable this way.
- Create a new page
On the Lightning App Builder page, click New. Choose the page type you need: App Page, Home Page, or Record Page. Pick a layout template, give the page a label, and click Finish to open the drag-and-drop canvas.
- Drag components and set properties
From the Components panel on the left, drag standard or custom components into the canvas regions. Select each component to edit its properties in the right panel. Add Dynamic Forms field sections on a record page to place individual fields instead of one layout.
- Save and activate
Click Save, then Activate. Choose how the page is assigned: as the org default, an app default, or an app-and-profile combination. Activation is what makes your users actually see the page, so do not skip it.
App Page, Home Page, or Record Page. The type controls where the page can be assigned and which components are available.
The region structure of the page, such as one region, two regions, or a header plus columns. You can change components later but the template sets the frame.
Org default, app default, or app and profile. This decides exactly which users and apps load your new page.
- There is no Setup node literally named "Lightning Platform Builder." Search for the specific builder you need instead.
- A saved Lightning page does nothing until you activate it. Unactivated pages are a common reason changes seem to disappear.
- Use Object Manager, not Schema Builder, for production field changes. Schema Builder is best for visual modeling and documentation.
- Start new automation in Flow Builder. Workflow Rules are retired and Process Builder should not be used for new work.