How to enforce data validation in Bubble

The core way to enforce data validation in Bubble is to combine input conditions, workflow checks, and especially Privacy Rules + “Make changes/Create only if…” constraints. Validation in Bubble is not automatic, so you must manually block bad data before it reaches the database. The most reliable layer is the workflow’s “Only when” conditions, because they run even if someone bypasses the UI.

What Data Validation Really Means in Bubble

Validation is making sure users can save data only if it meets your rules. In Bubble, this happens in three layers: the UI, the workflow, and privacy.

• UI-level: Disable submit buttons until inputs are valid (e.g., “This input is not empty”).
• Workflow-level: In “Create a new thing” or “Make changes to thing”, add an Only when condition so invalid data never saves.
• Privacy-level: Prevent unwanted fields from ever being written unless conditions are met.

How to Actually Implement It

• Use “Only when” on the workflow action. Example: A user shouldn’t create an Event unless the title is filled and the date is in the future.

// Workflow action: Create a new Event
Only when: Input Title's value is not empty  
  and Date Picker's value > Current date/time

• Use “This input should not be empty” on inputs. This prevents clicking the button too early, but remember: users can still bypass UI checks, so keep workflow logic.
• Use Regex validation on inputs when needed. Example: email formats, code formats, etc.
• Use Privacy Rules to block writes. Example: Only allow “Created by is Current User”. If a workflow tries to write disallowed data, Bubble blocks it.
• Use Option Sets when values must be restricted. This prevents invalid text from ever being stored.

Final Practical Example

You want to enforce that a “User Profile” must have an age ≥ 18.

• UI: Show a red alert when Input Age < 18.
• Workflow: In “Make changes to Current User” add Only when: Input Age's value ≥ 18
• Privacy: Block writing to “age” unless “This User is Current User”.

// Workflow: Make changes to Current User
Only when: Input Age's value >= 18

This guarantees nobody can save invalid age data, even through custom API calls or disabled UI.