Why does Mouse On Click fire on a tablet tap?

Browsers simulate mouse events from touches for compatibility. Construct 3 receives both: a Touch event and a synthesized Mouse event. If both have handlers, your action fires twice. Use only Touch on Tap on mobile or set a flag to consume one of them.

How do I make a button work on both desktop and mobile in Construct 3?

Use Touch On Tap (or On Touched Object) which fires on both touch and (depending on settings) mouse-down. Avoid duplicating logic in Mouse On Click and Touch On Tap; pick one event source per action.

Why does Touch.IsInTouch work but Mouse.LeftButton return false on tablets?

Some browsers and Construct configurations do not synthesize button-down events even though clicks fire. Trust IsInTouch over Mouse.LeftButton for cross-platform code. Or use Touch object with Mouse Input enabled to unify them.

Fix: Construct 3 Mouse Click Firing Twice on Touch

Quick answer: Browsers fire both a Touch event and a synthetic Mouse event for taps. Avoid handling both. Use the Touch object with Use Mouse Input enabled, or write logic only against Touch and ignore Mouse on mobile platforms.

Here is how to fix Construct 3 actions that run twice on tablets and phones — once for the touch event, once for the synthesized mouse event the browser also fires. The double-fire is invisible on desktop where touch is absent. On mobile, every tap costs the player two of whatever the action did. The fix is consolidating input handling on a single source.

The Symptom

A button on a tablet plays its sound twice per tap. Or a counter increments by 2 per click. Or a dialog confirms then immediately re-confirms. Desktop with mouse-only input behaves correctly.

What Causes This

Browser synthesizes mouse from touch. Web browsers fire touchstart, touchend, then often a mousedown/mouseup/click trio for every tap to support legacy code. Construct 3 surfaces both.

Both Mouse and Touch handlers active. Your event sheet has Mouse On Click and Touch On Tap on the same target. Both fire.

Touch object Mouse Input setting. The Touch object has a Use Mouse Input property that lets desktop mouse drive Touch events too. With it on, you can rely on Touch alone for both platforms.

The Fix

Step 1: Use Touch with Mouse Input. Add a Touch object to the project. Open its Properties and enable Use Mouse Input. Now Touch.On Tap fires for both touch and mouse clicks. You can delete Mouse handlers entirely.

Step 2: Consolidate logic on Touch.

Event: Touch -> On tap on Button
  Action: Audio -> Play click sound
  Action: System -> Add 1 to score

Remove any Mouse On Click event for the same button.

Step 3: If you must use Mouse, gate by platform.

Event: Browser -> Is on platform "Desktop"
  Sub-event: Mouse -> On Left button Clicked on Button
    Action: handle click

Event: Browser -> Is on platform "Mobile"
  Sub-event: Touch -> On tap on Button
    Action: handle click

This avoids double-fire by branching, but Touch with Mouse Input is simpler.

Step 4: For continuous input, use IsInTouch.

Event: Touch.IsInTouch
  Action: Player -> Set position to (Touch.X, Touch.Y)

Touch.IsInTouch works for both pointer-down and finger-down when Mouse Input is enabled.

Step 5: Disable browser-default touch effects. Some browsers apply visual feedback or scrolling for touches. To prevent unintended interactions, in Project → Properties set Disable Touch Defaults to On.

Cross-Platform Best Practice

Always plan input on Touch as the primary source with Use Mouse Input enabled. This unifies behavior across desktop and mobile, eliminates double-fire, and keeps your event sheet smaller. Reserve Mouse-specific events for desktop-only features (right-click context menus, hover effects).

“Touch with Mouse Input handles both platforms. One event source, no double-fires.”

Related Issues

For touch input not working on mobile, see Touch Input Not Working. For pinch zoom issues, see Pinch Zoom Wrong Center.

Touch object. Use Mouse Input. Single event handler. The double-fire stops.