diff --git a/lightningbeam-ui/lightningbeam-core/src/actions/mod.rs b/lightningbeam-ui/lightningbeam-core/src/actions/mod.rs
index 34bac39..352bae3 100644
--- a/lightningbeam-ui/lightningbeam-core/src/actions/mod.rs
+++ b/lightningbeam-ui/lightningbeam-core/src/actions/mod.rs
@@ -32,6 +32,7 @@ pub mod region_split;
 pub mod toggle_group_expansion;
 pub mod group_layers;
 pub mod raster_stroke;
+pub mod raster_fill;
 pub mod move_layer;
 
 pub use add_clip_instance::AddClipInstanceAction;
@@ -63,4 +64,5 @@ pub use region_split::RegionSplitAction;
 pub use toggle_group_expansion::ToggleGroupExpansionAction;
 pub use group_layers::GroupLayersAction;
 pub use raster_stroke::RasterStrokeAction;
+pub use raster_fill::RasterFillAction;
 pub use move_layer::MoveLayerAction;
diff --git a/lightningbeam-ui/lightningbeam-core/src/actions/raster_fill.rs b/lightningbeam-ui/lightningbeam-core/src/actions/raster_fill.rs
new file mode 100644
index 0000000..38a4358
--- /dev/null
+++ b/lightningbeam-ui/lightningbeam-core/src/actions/raster_fill.rs
@@ -0,0 +1,58 @@
+//! Raster flood-fill action — records and undoes a paint bucket fill on a RasterLayer.
+
+use crate::action::Action;
+use crate::document::Document;
+use crate::layer::AnyLayer;
+use uuid::Uuid;
+
+pub struct RasterFillAction {
+    layer_id: Uuid,
+    time: f64,
+    buffer_before: Vec<u8>,
+    buffer_after: Vec<u8>,
+    width: u32,
+    height: u32,
+}
+
+impl RasterFillAction {
+    pub fn new(
+        layer_id: Uuid,
+        time: f64,
+        buffer_before: Vec<u8>,
+        buffer_after: Vec<u8>,
+        width: u32,
+        height: u32,
+    ) -> Self {
+        Self { layer_id, time, buffer_before, buffer_after, width, height }
+    }
+}
+
+impl Action for RasterFillAction {
+    fn execute(&mut self, document: &mut Document) -> Result<(), String> {
+        let layer = document.get_layer_mut(&self.layer_id)
+            .ok_or_else(|| format!("Layer {} not found", self.layer_id))?;
+        let raster = match layer {
+            AnyLayer::Raster(rl) => rl,
+            _ => return Err("Not a raster layer".to_string()),
+        };
+        let kf = raster.ensure_keyframe_at(self.time, self.width, self.height);
+        kf.raw_pixels = self.buffer_after.clone();
+        Ok(())
+    }
+
+    fn rollback(&mut self, document: &mut Document) -> Result<(), String> {
+        let layer = document.get_layer_mut(&self.layer_id)
+            .ok_or_else(|| format!("Layer {} not found", self.layer_id))?;
+        let raster = match layer {
+            AnyLayer::Raster(rl) => rl,
+            _ => return Err("Not a raster layer".to_string()),
+        };
+        let kf = raster.ensure_keyframe_at(self.time, self.width, self.height);
+        kf.raw_pixels = self.buffer_before.clone();
+        Ok(())
+    }
+
+    fn description(&self) -> String {
+        "Flood fill".to_string()
+    }
+}
diff --git a/lightningbeam-ui/lightningbeam-core/src/flood_fill.rs b/lightningbeam-ui/lightningbeam-core/src/flood_fill.rs
index 023cea2..99ba88a 100644
--- a/lightningbeam-ui/lightningbeam-core/src/flood_fill.rs
+++ b/lightningbeam-ui/lightningbeam-core/src/flood_fill.rs
@@ -1,8 +1,172 @@
-//! Flood fill algorithm for paint bucket tool
+//! Flood fill algorithms for paint bucket tool
 //!
-//! This module implements a flood fill that tracks which curves each point
-//! touches. Instead of filling with pixels, it returns boundary points that
-//! can be used to construct a filled shape from exact curve geometry.
+//! This module contains two fill implementations:
+//! - `flood_fill` — vector curve-boundary fill (used by vector paint bucket)
+//! - `raster_flood_fill` — pixel BFS fill with configurable threshold, soft
+//!   edge, and optional selection clipping (used by raster paint bucket)
+
+// ── Raster flood fill ─────────────────────────────────────────────────────────
+
+/// Which pixel to compare against when deciding if a neighbor should be filled.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum FillThresholdMode {
+    /// Compare each candidate pixel to the original seed pixel (Photoshop default).
+    Absolute,
+    /// Compare each candidate pixel to the pixel it was reached from (spreads
+    /// through gradients without a global seed-color reference).
+    Relative,
+}
+
+/// Pixel flood fill for the raster paint bucket tool.
+///
+/// Operates on a flat RGBA `Vec<u8>` (4 bytes per pixel, row-major).
+/// Pixels are alpha-composited with `fill_color` — the existing canvas content
+/// shows through wherever `fill_color` has partial transparency or softness
+/// reduces its effective alpha.
+///
+/// # Parameters
+/// - `pixels`     – raw RGBA buffer, modified in place
+/// - `width/height` – canvas dimensions
+/// - `seed_x/y`  – click coordinates (canvas pixel indices, 0-based)
+/// - `fill_color` – RGBA fill \[r, g, b, a\], 0–255 each
+/// - `threshold`  – max color distance (Euclidean RGBA) to include in fill (0–255·√4 ≈ 510)
+/// - `softness`   – how much of the threshold is a soft fade (0 = hard edge, 100 = full fade)
+/// - `mode`       – compare candidates to seed (Absolute) or to their BFS parent (Relative)
+/// - `selection`  – optional clip mask; pixels outside are never filled
+pub fn raster_flood_fill(
+    pixels: &mut Vec<u8>,
+    width: u32,
+    height: u32,
+    seed_x: i32,
+    seed_y: i32,
+    fill_color: [u8; 4],
+    threshold: f32,
+    softness: f32,
+    mode: FillThresholdMode,
+    selection: Option<&crate::selection::RasterSelection>,
+) {
+    use std::collections::VecDeque;
+
+    let w = width as i32;
+    let h = height as i32;
+    let n = (width * height) as usize;
+
+    if seed_x < 0 || seed_y < 0 || seed_x >= w || seed_y >= h { return; }
+
+    let seed_idx = (seed_y * w + seed_x) as usize;
+    let seed_color = [
+        pixels[seed_idx * 4],
+        pixels[seed_idx * 4 + 1],
+        pixels[seed_idx * 4 + 2],
+        pixels[seed_idx * 4 + 3],
+    ];
+
+    // dist_map[i] = Some(d) when pixel i is within the fill region with
+    // color-distance `d` from its comparison color.
+    let mut dist_map: Vec<Option<f32>> = vec![None; n];
+    let mut queue: VecDeque<(i32, i32)> = VecDeque::new();
+
+    // Track the pixel that each BFS node was reached from (for Relative mode).
+    // In Absolute mode this is ignored (we always compare to seed_color).
+    let mut parent_color: Vec<[u8; 4]> = vec![[0; 4]; n];
+
+    dist_map[seed_idx] = Some(0.0);
+    parent_color[seed_idx] = seed_color;
+    queue.push_back((seed_x, seed_y));
+
+    let dirs: [(i32, i32); 4] = [(0, -1), (0, 1), (-1, 0), (1, 0)];
+
+    while let Some((cx, cy)) = queue.pop_front() {
+        let ci = (cy * w + cx) as usize;
+
+        let compare_color = match mode {
+            FillThresholdMode::Absolute => seed_color,
+            FillThresholdMode::Relative => parent_color[ci],
+        };
+
+        for (dx, dy) in dirs {
+            let nx = cx + dx;
+            let ny = cy + dy;
+            if nx < 0 || ny < 0 || nx >= w || ny >= h { continue; }
+            let ni = (ny * w + nx) as usize;
+            if dist_map[ni].is_some() { continue; }
+            if let Some(sel) = selection {
+                if !sel.contains_pixel(nx, ny) { continue; }
+            }
+            let npx = [
+                pixels[ni * 4],
+                pixels[ni * 4 + 1],
+                pixels[ni * 4 + 2],
+                pixels[ni * 4 + 3],
+            ];
+            let d = color_distance(npx, compare_color);
+            if d <= threshold {
+                dist_map[ni] = Some(d);
+                parent_color[ni] = npx;
+                queue.push_back((nx, ny));
+            }
+        }
+    }
+
+    // Write pass: alpha-composite fill_color over existing pixels.
+    let fr = fill_color[0] as f32 / 255.0;
+    let fg = fill_color[1] as f32 / 255.0;
+    let fb = fill_color[2] as f32 / 255.0;
+    let fa_base = fill_color[3] as f32 / 255.0;
+
+    // Softness defines what fraction of [0..threshold] uses full alpha vs fade.
+    // falloff_start_ratio: distance ratio at which the fade begins (0→full fade, 1→hard).
+    let falloff_start = if softness <= 0.0 || threshold <= 0.0 {
+        1.0_f32 // hard edge: never start fading
+    } else {
+        1.0 - softness / 100.0
+    };
+
+    for i in 0..n {
+        if let Some(d) = dist_map[i] {
+            let alpha = if threshold <= 0.0 {
+                fa_base
+            } else {
+                let t = d / threshold; // 0.0 at seed, 1.0 at boundary
+                if t <= falloff_start {
+                    fa_base
+                } else {
+                    let frac = (t - falloff_start) / (1.0 - falloff_start).max(1e-6);
+                    fa_base * (1.0 - frac)
+                }
+            };
+
+            if alpha <= 0.0 { continue; }
+
+            // Porter-Duff "src over dst" with straight alpha.
+            let dst_r = pixels[i * 4    ] as f32 / 255.0;
+            let dst_g = pixels[i * 4 + 1] as f32 / 255.0;
+            let dst_b = pixels[i * 4 + 2] as f32 / 255.0;
+            let dst_a = pixels[i * 4 + 3] as f32 / 255.0;
+
+            let inv_a = 1.0 - alpha;
+            let out_a = alpha + dst_a * inv_a;
+            if out_a > 0.0 {
+                pixels[i * 4    ] = ((fr * alpha + dst_r * dst_a * inv_a) / out_a * 255.0).round() as u8;
+                pixels[i * 4 + 1] = ((fg * alpha + dst_g * dst_a * inv_a) / out_a * 255.0).round() as u8;
+                pixels[i * 4 + 2] = ((fb * alpha + dst_b * dst_a * inv_a) / out_a * 255.0).round() as u8;
+                pixels[i * 4 + 3] = (out_a * 255.0).round() as u8;
+            }
+        }
+    }
+}
+
+fn color_distance(a: [u8; 4], b: [u8; 4]) -> f32 {
+    let dr = a[0] as f32 - b[0] as f32;
+    let dg = a[1] as f32 - b[1] as f32;
+    let db = a[2] as f32 - b[2] as f32;
+    let da = a[3] as f32 - b[3] as f32;
+    (dr * dr + dg * dg + db * db + da * da).sqrt()
+}
+
+// ── Vector (curve-boundary) flood fill ───────────────────────────────────────
+// The following is the original vector-layer flood fill, kept for the vector
+// paint bucket tool.
 
 use crate::curve_segment::CurveSegment;
 use crate::quadtree::{BoundingBox, Quadtree};
diff --git a/lightningbeam-ui/lightningbeam-editor/src/panes/infopanel.rs b/lightningbeam-ui/lightningbeam-editor/src/panes/infopanel.rs
index c1bbc3b..b8809b3 100644
--- a/lightningbeam-ui/lightningbeam-editor/src/panes/infopanel.rs
+++ b/lightningbeam-ui/lightningbeam-editor/src/panes/infopanel.rs
@@ -278,15 +278,52 @@ impl InfopanelPane {
                     }
 
                     Tool::PaintBucket => {
-                        // Gap tolerance
-                        ui.horizontal(|ui| {
-                            ui.label("Gap Tolerance:");
-                            ui.add(
-                                DragValue::new(shared.paint_bucket_gap_tolerance)
-                                    .speed(0.1)
-                                    .range(0.0..=50.0),
-                            );
-                        });
+                        if active_is_raster {
+                            use crate::tools::FillThresholdMode;
+                            ui.horizontal(|ui| {
+                                ui.label("Threshold:");
+                                ui.add(
+                                    egui::Slider::new(
+                                        &mut shared.raster_settings.fill_threshold,
+                                        0.0_f32..=255.0,
+                                    )
+                                    .step_by(1.0),
+                                );
+                            });
+                            ui.horizontal(|ui| {
+                                ui.label("Softness:");
+                                ui.add(
+                                    egui::Slider::new(
+                                        &mut shared.raster_settings.fill_softness,
+                                        0.0_f32..=100.0,
+                                    )
+                                    .custom_formatter(|v, _| format!("{:.0}%", v)),
+                                );
+                            });
+                            ui.horizontal(|ui| {
+                                ui.label("Mode:");
+                                ui.selectable_value(
+                                    &mut shared.raster_settings.fill_threshold_mode,
+                                    FillThresholdMode::Absolute,
+                                    "Absolute",
+                                );
+                                ui.selectable_value(
+                                    &mut shared.raster_settings.fill_threshold_mode,
+                                    FillThresholdMode::Relative,
+                                    "Relative",
+                                );
+                            });
+                        } else {
+                            // Vector: gap tolerance
+                            ui.horizontal(|ui| {
+                                ui.label("Gap Tolerance:");
+                                ui.add(
+                                    DragValue::new(shared.paint_bucket_gap_tolerance)
+                                        .speed(0.1)
+                                        .range(0.0..=50.0),
+                                );
+                            });
+                        }
                     }
 
                     Tool::Polygon => {
diff --git a/lightningbeam-ui/lightningbeam-editor/src/panes/stage.rs b/lightningbeam-ui/lightningbeam-editor/src/panes/stage.rs
index ba5ff9c..be91fbc 100644
--- a/lightningbeam-ui/lightningbeam-editor/src/panes/stage.rs
+++ b/lightningbeam-ui/lightningbeam-editor/src/panes/stage.rs
@@ -5669,31 +5669,28 @@ impl StagePane {
         shared: &mut SharedPaneState,
     ) {
         use lightningbeam_core::layer::AnyLayer;
-        use lightningbeam_core::shape::ShapeColor;
-        use lightningbeam_core::actions::PaintBucketAction;
-        use vello::kurbo::Point;
 
-        // Check if we have an active vector layer
         let active_layer_id = match shared.active_layer_id {
-            Some(id) => id,
+            Some(id) => *id,
             None => return,
         };
 
-        let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
-            Some(layer) => layer,
-            None => return,
-        };
+        if !self.rsp_clicked(response) { return; }
 
-        if !matches!(active_layer, AnyLayer::Vector(_)) {
-            return;
-        }
+        let is_raster = shared.action_executor.document()
+            .get_layer(&active_layer_id)
+            .map_or(false, |l| matches!(l, AnyLayer::Raster(_)));
 
-        if self.rsp_clicked(response) {
+        if is_raster {
+            self.handle_raster_paint_bucket(world_pos, active_layer_id, shared);
+        } else {
+            use lightningbeam_core::shape::ShapeColor;
+            use lightningbeam_core::actions::PaintBucketAction;
+            use vello::kurbo::Point;
             let click_point = Point::new(world_pos.x as f64, world_pos.y as f64);
             let fill_color = ShapeColor::from_egui(*shared.fill_color);
-
             let action = PaintBucketAction::new(
-                *active_layer_id,
+                active_layer_id,
                 *shared.playback_time,
                 click_point,
                 fill_color,
@@ -5702,6 +5699,77 @@ impl StagePane {
         }
     }
 
+    fn handle_raster_paint_bucket(
+        &mut self,
+        world_pos: egui::Vec2,
+        layer_id: uuid::Uuid,
+        shared: &mut SharedPaneState,
+    ) {
+        use lightningbeam_core::layer::AnyLayer;
+        use lightningbeam_core::actions::RasterFillAction;
+        use lightningbeam_core::flood_fill::{raster_flood_fill, FillThresholdMode};
+        use crate::tools::FillThresholdMode as EditorMode;
+
+        let time = *shared.playback_time;
+
+        // Ensure a keyframe exists at the current time.
+        let (doc_w, doc_h) = {
+            let doc = shared.action_executor.document();
+            (doc.width as u32, doc.height as u32)
+        };
+        {
+            let doc = shared.action_executor.document_mut();
+            if let Some(AnyLayer::Raster(rl)) = doc.get_layer_mut(&layer_id) {
+                rl.ensure_keyframe_at(time, doc_w, doc_h);
+            }
+        }
+
+        // Snapshot current pixels.
+        let (buffer_before, width, height) = {
+            let doc = shared.action_executor.document();
+            if let Some(AnyLayer::Raster(rl)) = doc.get_layer(&layer_id) {
+                if let Some(kf) = rl.keyframe_at(time) {
+                    let expected = (kf.width * kf.height * 4) as usize;
+                    let buf = if kf.raw_pixels.len() == expected {
+                        kf.raw_pixels.clone()
+                    } else {
+                        vec![0u8; expected]
+                    };
+                    (buf, kf.width, kf.height)
+                } else { return; }
+            } else { return; }
+        };
+
+        let seed_x = world_pos.x as i32;
+        let seed_y = world_pos.y as i32;
+        if seed_x < 0 || seed_y < 0 || seed_x >= width as i32 || seed_y >= height as i32 {
+            return;
+        }
+
+        let fill_egui = *shared.fill_color;
+        let fill_color = [fill_egui.r(), fill_egui.g(), fill_egui.b(), fill_egui.a()];
+        let threshold  = shared.raster_settings.fill_threshold;
+        let softness   = shared.raster_settings.fill_softness;
+        let core_mode  = match shared.raster_settings.fill_threshold_mode {
+            EditorMode::Absolute => FillThresholdMode::Absolute,
+            EditorMode::Relative => FillThresholdMode::Relative,
+        };
+
+        let mut buffer_after = buffer_before.clone();
+        raster_flood_fill(
+            &mut buffer_after,
+            width, height,
+            seed_x, seed_y,
+            fill_color,
+            threshold, softness,
+            core_mode,
+            shared.selection.raster_selection.as_ref(),
+        );
+
+        let action = RasterFillAction::new(layer_id, time, buffer_before, buffer_after, width, height);
+        let _ = shared.action_executor.execute(Box::new(action));
+    }
+
     /// Apply transform preview to objects based on current mouse position
     fn apply_transform_preview(
         vector_layer: &mut lightningbeam_core::layer::VectorLayer,
diff --git a/lightningbeam-ui/lightningbeam-editor/src/tools/mod.rs b/lightningbeam-ui/lightningbeam-editor/src/tools/mod.rs
index 55039db..71ccae3 100644
--- a/lightningbeam-ui/lightningbeam-editor/src/tools/mod.rs
+++ b/lightningbeam-ui/lightningbeam-editor/src/tools/mod.rs
@@ -77,6 +77,25 @@ pub struct RasterToolSettings {
     pub blur_sharpen_kernel: f32,
     /// 0 = blur, 1 = sharpen
     pub blur_sharpen_mode: u32,
+    // --- Flood fill (Paint Bucket, raster) ---
+    /// Color-distance threshold (Euclidean RGBA, 0–510). Pixels within this
+    /// distance of the comparison color are included in the fill.
+    pub fill_threshold: f32,
+    /// Soft-edge width as a percentage of the threshold (0 = hard, 100 = full fade).
+    pub fill_softness: f32,
+    /// Whether to compare each pixel to the seed pixel (Absolute) or to its BFS
+    /// parent pixel (Relative, spreads across gradients).
+    pub fill_threshold_mode: FillThresholdMode,
+}
+
+/// Threshold comparison mode for the raster flood fill.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub enum FillThresholdMode {
+    /// Compare each candidate pixel to the original seed pixel (default).
+    #[default]
+    Absolute,
+    /// Compare each candidate pixel to the pixel it was reached from.
+    Relative,
 }
 
 impl Default for RasterToolSettings {
@@ -120,6 +139,9 @@ impl Default for RasterToolSettings {
             blur_sharpen_strength: 0.5,
             blur_sharpen_kernel: 5.0,
             blur_sharpen_mode: 0,
+            fill_threshold: 15.0,
+            fill_softness: 0.0,
+            fill_threshold_mode: FillThresholdMode::Absolute,
         }
     }
 }