Quick answer: Use get_viewport().get_mouse_position() to get coordinates in the correct viewport. For world-space coordinates, use get_global_mouse_position() on a Node2D. Inside a SubViewport, you must account for the SubViewportContainer offset and scale.

Here is how to fix Godot viewport mouse position offset. You draw a cursor at the mouse location and it appears shifted by a fixed amount. You click an Area2D at the pointer and the click lands elsewhere. You set up a minimap in a SubViewport and its mouse handling is off by the container position. Godot has four separate mouse-position getters, each measuring in a different space, and picking the wrong one is a common source of subtle offset bugs.

The Symptom

A cursor follows the mouse but appears shifted by the title bar height, or by some fixed constant. A click registers at a position different from where you see the pointer. A SubViewport-based minimap reports mouse positions relative to the main window instead of the minimap contents.

Variant: positions are correct in windowed mode but offset in fullscreen or after resizing. Or positions scale correctly but are translated by a fixed margin.

What Causes This

Wrong getter for the space. Godot has:

Using the wrong one for your task produces a consistent offset.

Stretch mode. Project Settings > Display > Window > Stretch > Mode can be disabled, canvas_items, or viewport. viewport renders at a fixed internal size and stretches. Mouse coordinates returned by viewport methods are in this logical size, not pixels.

SubViewport without a SubViewportContainer transform. Placing a SubViewport in a scene and displaying it somewhere creates a mismatch: the mouse events you receive are in the display space, but drawing inside the SubViewport uses SubViewport-space. Without explicit transformation, cursor sprites appear offset.

Camera2D zoom. A Camera2D with zoom != 1.0 changes the mapping between screen and world. get_global_mouse_position accounts for the active camera; get_viewport().get_mouse_position() does not.

Window mode vs exclusive fullscreen. Exclusive fullscreen may report coordinates without the title-bar offset, while windowed mode includes it from some APIs.

The Fix

Step 1: Use the right getter.

extends Node2D

func _process(_delta):
    # World-space mouse (respects camera zoom and position)
    var world_pos = get_global_mouse_position()

    # Viewport-space (ignores camera)
    var view_pos = get_viewport().get_mouse_position()

    # Local to this node's transform
    var local_pos = get_local_mouse_position()

    print("world ", world_pos, " view ", view_pos, " local ", local_pos)

For positioning a cursor sprite in the world, use get_global_mouse_position. For Control-node UI positioning, use get_viewport().get_mouse_position(). They are not interchangeable.

Step 2: Set the stretch mode you actually want. In Project Settings:

For pixel-art games, use canvas_items with integer stretch mode. The viewport reports logical coordinates, which is what you want for gameplay.

Step 3: Map mouse into a SubViewport. Wrap the SubViewport in a SubViewportContainer and use its transform to convert the outer mouse position:

extends SubViewportContainer

func _gui_input(event: InputEvent):
    if event is InputEventMouseMotion:
        var sub = $SubViewport
        # event.position is already relative to this container
        var in_sub = event.position * sub.size / size
        sub.push_input(event.duplicate())

Setting SubViewportContainer.stretch = true auto-forwards mouse events with correct scaling. Prefer this over manual math when you can.

Step 4: Account for Camera2D zoom when reading input. get_global_mouse_position already handles zoom. If you are reading Input.get_mouse_position() manually, multiply by the inverse of the canvas transform:

var screen = Input.get_mouse_position()
var world = get_canvas_transform().affine_inverse() * screen

Debugging the Offset

Draw a debug label at the mouse position and compare to what your game thinks is the mouse position:

func _draw():
    var p = get_global_mouse_position() - global_position
    draw_circle(p, 6, Color.RED)

If the red circle follows the cursor exactly, your math is right. If it sits at a fixed offset, you are using the wrong coordinate space.

Understanding the issue

This bug class falls into a pattern that's worth understanding beyond the specific case. In Godot Engine, the underlying behavior is shaped by how the engine layers its abstractions - the public API you call, the runtime systems that respond, and the platform-specific implementations underneath. A bug at any layer can produce symptoms that look like they originate at a different layer. Triaging effectively means recognizing which layer the symptom belongs to, even when the gameplay code is what's visible.

The specific bug described above is the kind that surfaces during integration rather than unit testing. It depends on a combination of factors: the asset configuration, the runtime state, the platform's specific behavior. In isolation, each piece looks correct; in combination, the bug emerges. This is why thorough integration testing - playing the actual game in realistic conditions - catches things that automated tests miss.

Why this happens

Bugs of this class are particularly easy to ship past internal QA because they often depend on specific runtime conditions - hardware combinations, network states, or asset configurations that QA didn't reproduce. Players hit them in the wild, file reports that are hard to repro, and the bug accumulates negative reviews while engineering tries to recreate the failure mode.

At the engine level, the behavior comes from a deliberate design decision in Godot. The engine team chose a particular trade-off - usually performance versus convenience, or generality versus specificity - and that trade-off has consequences when you push against it. Understanding the trade-off is what turns 'this bug is mysterious' into 'this bug is the expected consequence of this design'.

Verifying the fix

After applying the fix, the verification step has three parts: confirm the original repro is resolved, confirm no obvious regressions in adjacent functionality, and (for shipping titles) deploy to a small player cohort first and watch the crash and report rates. Each step catches something the others miss.

Reproducibility is the prerequisite for verification. If you can't reliably reproduce the bug pre-fix, you can't reliably verify it post-fix. Spend time getting a clean reproduction before you write any fix code. The fix is fast once you understand the reproduction; the reproduction is the slow part.

Variations to watch for

There's almost always a less obvious case where the same problem applies. The reported case is the one a player hit; the related cases hide because they're rarer or affect fewer players. After fixing the reported case, search the codebase for the pattern - one fix often unlocks several.

Adjacent bugs often share a root cause. After fixing the case you've found, spend an hour searching the codebase for similar patterns. What's the same call with different arguments? The same data flow with a different entity type? The same lifecycle issue in a sibling system? Each match is a candidate for the same fix, or a related fix that prevents future bugs of the same class.

In production

Live games surface this bug class at scale. What's a rare edge case in development becomes a daily occurrence once you have a few thousand concurrent players. The class isn't 'this player has a unique setup'; it's 'one in N thousand sessions will trigger this exact combination'.

When triaging a similar issue in production, prioritize gathering data over hypothesizing causes. A player report describes a symptom; what you need is a build SHA, a session timestamp, and ideally a screen recording or session replay. With those, the bug becomes tractable. Without them, you're guessing at hypothetical reproductions that may not match what the player actually hit.

Performance considerations

If this issue manifests under high load (many actors, many particles, many network connections), profile the post-fix code path with realistic counts. The original cost was a bug; the new cost is real work, and real work has a budget.

Diagnostic approach

Diagnosing this class of bug benefits from a structured approach: confirm the symptom, isolate the variables, hypothesize the cause, and verify the hypothesis before writing fix code. Skipping the isolation step is the most common mistake; without it, fixes often address symptoms while the underlying cause continues to produce other variations.

For Godot-specific diagnostics, the editor's profiler is the canonical starting point. Capture a representative frame with the symptom present; compare against a frame without the symptom; the diff often points directly at the cause. If the symptom is non-deterministic, capture multiple frames and look for the pattern - the cause is usually a state transition or a specific input value rather than a continuous effect.

Tooling and ecosystem

The tooling around this bug class matters as much as the fix itself. Good logging, accessible profilers, and clear error messages turn 30-minute investigations into 5-minute ones. If your project doesn't have visibility into this code path, the first fix should add the visibility - the second fix uses it.

Within Godot, the relevant diagnostic surfaces include the standard frame debugger, memory profiler, and engine-specific debug overlays. Each one shows a different facet of what's happening. The frame debugger reveals draw call ordering and state transitions; the memory profiler shows allocation patterns; the debug overlay reveals per-system state. Bugs that resist one tool usually surrender to another - the trick is knowing which tool to reach for first.

Edge cases and pitfalls

Platform-specific edge cases are worth enumerating explicitly. iOS handles backgrounding differently than Android; Windows handles focus changes differently than macOS. A fix that works on the development platform may not work on every target. Test on each shipping platform deliberately.

When writing a regression test for this fix, focus on the boundary conditions that surfaced the original bug. Tests that exercise the happy path catch obvious regressions; tests that exercise the boundary catch the subtler regressions that look like new bugs but are really the original returning. The latter are the tests that earn their keep over the long life of the project.

Team communication

When this bug class affects multiple teams (often the case for cross-system issues), early communication prevents duplicate work. The team that owns the symptom may not own the cause. A 15-minute conversation at the start of triage often saves hours of independent investigation.

If this fix touches a system several engineers work in, a short writeup in the team's engineering channel helps. Not a full design doc - a paragraph explaining what was wrong, what's fixed, and what to watch for. Future engineers encountering similar symptoms will search for the fix; making it findable is a small investment that pays back later.

“Four mouse-position getters. Four different spaces. Pick the one that matches where you want to draw.”

Related Issues

For UI input handling, see Area2D Not Detecting StaticBody2D. For stretch and scaling concerns across displays, Label3D Render Depth Wrong covers related 3D display topics.

get_global_mouse_position for world, get_viewport for UI, SubViewport needs a container. Coordinates line up.