diff --git a/CHANGELOG.md b/CHANGELOG.md
index 93644db..47870bc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Optional whole-toast `opacity()` styling with clamping, sparse updates, preset support, and PHP/JavaScript parity.
 - Platform-selective `native()` rendering with iOS Liquid Glass/native material fallback, Android Material 3 appearance, sparse update support, presets, and JavaScript parity.
 - Unique toasts through `unique()`, `updateUnique()`, and `dismissUnique()`, with native lifecycle-aware deduplication across visible, queued, stacked, and persistent states on Android and iOS.
 - JavaScript parity for unique toast creation, updates, dismissal, and bridge-resolved UUIDs.
diff --git a/README.md b/README.md
index e3cf442..713766b 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,7 @@ ToastKit renders toasts as native overlays — Jetpack Compose on Android, Swift
   - [Updating Toasts](#updating-toasts)
   - [Unique Toasts](#unique-toasts)
   - [Native Appearance](#native-appearance)
+  - [Opacity](#opacity)
   - [Progress \& Loading](#progress--loading)
   - [Animations \& Direction](#animations--direction)
   - [Presets](#presets)
@@ -386,6 +387,24 @@ Toast::update($id)
 
 On iOS 26 and later, ToastKit uses Apple's system Liquid Glass effect. Earlier supported iOS versions use SwiftUI's native regular material. Android uses the official Material 3 `Snackbar` component inside ToastKit's existing overlay, retaining the established lifecycle and event pipeline.
 
+## Opacity
+
+Opacity is optional and applies to the entire toast, including its content and controls:
+
+```php
+Toast::success('Saved')->opacity()->show();      // 0.8
+Toast::success('Saved')->opacity(0.5)->show();   // 50%
+Toast::success('Saved')->opacity(1.0)->show();   // Fully opaque
+```
+
+If `opacity()` is never called, ToastKit behaves exactly as before. Accepted values are `0.0`–`1.0`; values outside that range are clamped. Opacity also works in presets and sparse updates:
+
+```php
+Toast::definePreset('subtle', fn ($toast) => $toast->opacity()->animation('fade'));
+
+Toast::update($id)->opacity(0.9)->show();
+```
+
 ## Progress & Loading
 
 Use determinate progress for work with a known percentage. Values are clamped to `0`–`100`, and updates animate without replacing the toast:
@@ -996,6 +1015,7 @@ Native::test(ProfileScreen::class)
 | `icon(?string $name = null, ?string $ios = null, ?string $android = null)` | Set an icon using string names, with optional SF Symbol (`ios:`) / Material Icon (`android:`) overrides. See [Icons](#icons). |
 | `position(ToastPosition\|string $position)` | `top`, `center`, or `bottom`. |
 | `native(bool $ios = true, bool $android = true)` | Use platform-native appearance selectively; custom rendering remains the default. |
+| `opacity(float $opacity = 0.8)` | Set whole-toast opacity from `0.0` to `1.0`; out-of-range values are clamped. |
 | `duration(int $milliseconds)` | Set the visible duration (makes the toast timed). |
 | `persistent(bool $persistent = true)` | Make the toast persistent (no timeout). |
 | `animation(ToastAnimation\|string $animation)` | `fade`, `slide`, `scale`, `spring`, `snap`, `pop`, `reveal`, or `bounce`. |
diff --git a/resources/android/src/com/victorycodedev/plugins/toastkit/bridge/ToastKitBridgeNormalizer.kt b/resources/android/src/com/victorycodedev/plugins/toastkit/bridge/ToastKitBridgeNormalizer.kt
index 871de1d..680d328 100644
--- a/resources/android/src/com/victorycodedev/plugins/toastkit/bridge/ToastKitBridgeNormalizer.kt
+++ b/resources/android/src/com/victorycodedev/plugins/toastkit/bridge/ToastKitBridgeNormalizer.kt
@@ -46,6 +46,7 @@ internal object ToastKitBridgeNormalizer {
             val mode = nativeMode(it)
             next = next.copy(nativeIos = mode.first, nativeAndroid = mode.second)
         }
+        if (changes.containsKey("opacity")) next = next.copy(opacity = opacity(changes["opacity"] ?: throw ToastKitInputException("opacity must be numeric")))
         if (changes.containsKey("progress")) next = next.copy(progress = optionalValue(changes["progress"])?.let(::progress))
         changes["loading"]?.let { next = next.copy(loading = boolean(it, "loading")) }
         changes["swipe_to_dismiss"]?.let { next = next.copy(swipeToDismiss = boolean(it, "swipe_to_dismiss")) }
@@ -74,6 +75,7 @@ internal object ToastKitBridgeNormalizer {
             uniqueKey = nullableString(values["unique_key"], "unique_key"),
             nativeIos = nativeMode(values["native"] ?: emptyMap<String, Any>()).first,
             nativeAndroid = nativeMode(values["native"] ?: emptyMap<String, Any>()).second,
+            opacity = values["opacity"]?.let(::opacity),
             message = requiredString(values, "message"),
             title = nullableString(values["title"], "title"),
             variant = variant(values["variant"] ?: "neutral"),
@@ -227,6 +229,11 @@ internal object ToastKitBridgeNormalizer {
         requireInput(result.isFinite(), "progress must be finite")
         return result.coerceIn(0f, 100f)
     }
+    private fun opacity(value: Any): Float {
+        val result = (value as? Number)?.toFloat() ?: throw ToastKitInputException("opacity must be numeric")
+        requireInput(result.isFinite(), "opacity must be finite")
+        return result.coerceIn(0f, 1f)
+    }
     private fun stringMap(value: Any?): Map<String, Any>? = when (value) {
         is JSONObject -> value.keys().asSequence().associate { key -> key to value.get(key) }
         is Map<*, *> -> value.entries.associate { (key, v) -> key.toString() to (v ?: JSONObject.NULL) }
diff --git a/resources/android/src/com/victorycodedev/plugins/toastkit/model/ToastKitModels.kt b/resources/android/src/com/victorycodedev/plugins/toastkit/model/ToastKitModels.kt
index 02a39b6..0addb56 100644
--- a/resources/android/src/com/victorycodedev/plugins/toastkit/model/ToastKitModels.kt
+++ b/resources/android/src/com/victorycodedev/plugins/toastkit/model/ToastKitModels.kt
@@ -34,6 +34,7 @@ internal data class ToastKitConfiguration(
     val uniqueKey: String?,
     val nativeIos: Boolean,
     val nativeAndroid: Boolean,
+    val opacity: Float?,
     val message: String,
     val title: String?,
     val variant: String,
diff --git a/resources/android/src/com/victorycodedev/plugins/toastkit/presentation/ToastKitHost.kt b/resources/android/src/com/victorycodedev/plugins/toastkit/presentation/ToastKitHost.kt
index 02b6cf9..fe3f155 100644
--- a/resources/android/src/com/victorycodedev/plugins/toastkit/presentation/ToastKitHost.kt
+++ b/resources/android/src/com/victorycodedev/plugins/toastkit/presentation/ToastKitHost.kt
@@ -23,6 +23,7 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.shadow
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.input.pointer.pointerInput
@@ -126,6 +127,7 @@ private fun ToastKitCard(toast: ToastKitConfiguration) {
     AnimatedVisibility(visibleState = visibility, enter = enter, exit = exit) {
         val interaction = Modifier.padding(vertical = 4.dp).widthIn(max = 560.dp).fillMaxWidth()
                 .graphicsLayer { translationX = displayedX; translationY = displayedY; alpha = (1f - (abs(displayedX) + abs(displayedY)) / 700f).coerceIn(.35f, 1f) }
+                .then(toast.opacity?.let { Modifier.alpha(it) } ?: Modifier)
                 .then(gesture)
         if (toast.nativeAndroid) {
             NativeToastKitCard(toast, displayedProgress, interaction)
diff --git a/resources/ios/Sources/Bridge/ToastKitBridgeNormalizer.swift b/resources/ios/Sources/Bridge/ToastKitBridgeNormalizer.swift
index 295349a..fe56862 100644
--- a/resources/ios/Sources/Bridge/ToastKitBridgeNormalizer.swift
+++ b/resources/ios/Sources/Bridge/ToastKitBridgeNormalizer.swift
@@ -50,6 +50,7 @@ enum ToastKitBridgeNormalizer {
             next.nativeIos = mode.ios
             next.nativeAndroid = mode.android
         }
+        if let value = changes["opacity"] { next.opacity = try opacity(value) }
         if changes.keys.contains("progress") { next.progress = try changes["progress"].map(progress) }
         if let value = changes["loading"] { next.loading = try boolean(value, "loading") }
         if let value = changes["swipe_to_dismiss"] { next.swipeToDismiss = try boolean(value, "swipe_to_dismiss") }
@@ -76,6 +77,7 @@ enum ToastKitBridgeNormalizer {
             uniqueKey: try nullableString(values["unique_key"], "unique_key"),
             nativeIos: try nativeMode(values["native"] ?? [String: Any]()).ios,
             nativeAndroid: try nativeMode(values["native"] ?? [String: Any]()).android,
+            opacity: try values["opacity"].map(opacity),
             message: try requiredString(values, "message"),
             title: try nullableString(values["title"], "title"),
             variant: variantName,
@@ -226,4 +228,10 @@ enum ToastKitBridgeNormalizer {
         }
         return min(100, max(0, result))
     }
+    private static func opacity(_ value: Any) throws -> Double {
+        guard let result = (value as? NSNumber)?.doubleValue, result.isFinite else {
+            throw ToastKitInputError.invalid("opacity must be a finite number")
+        }
+        return min(1, max(0, result))
+    }
 }
diff --git a/resources/ios/Sources/Model/ToastKitModels.swift b/resources/ios/Sources/Model/ToastKitModels.swift
index fd88646..1be42fd 100644
--- a/resources/ios/Sources/Model/ToastKitModels.swift
+++ b/resources/ios/Sources/Model/ToastKitModels.swift
@@ -41,6 +41,7 @@ struct ToastKitConfiguration: Identifiable {
     let uniqueKey: String?
     var nativeIos: Bool
     var nativeAndroid: Bool
+    var opacity: Double?
     var message: String
     var title: String?
     var variant: String
diff --git a/resources/ios/Sources/Presentation/ToastKitHost.swift b/resources/ios/Sources/Presentation/ToastKitHost.swift
index 67d8d84..d5caaff 100644
--- a/resources/ios/Sources/Presentation/ToastKitHost.swift
+++ b/resources/ios/Sources/Presentation/ToastKitHost.swift
@@ -99,6 +99,7 @@ private struct ToastKitView: View {
         }
         .offset(drag)
         .opacity(Double(max(CGFloat(0.35), CGFloat(1) - (abs(drag.width) + abs(drag.height)) / CGFloat(700))))
+        .toastKitConfiguredOpacity(toast.opacity)
         .contentShape(Rectangle())
         .background {
             GeometryReader { proxy in
@@ -224,6 +225,11 @@ private struct ToastKitFramePreferenceKey: PreferenceKey {
 }
 
 private extension View {
+    @ViewBuilder
+    func toastKitConfiguredOpacity(_ opacity: Double?) -> some View {
+        if let opacity { self.opacity(opacity) } else { self }
+    }
+
     @ViewBuilder
     func toastKitConditional<Content: View>(_ condition: Bool, transform: (Self) -> Content) -> some View {
         if condition { transform(self) } else { self }
diff --git a/resources/js/PendingToastBase.js b/resources/js/PendingToastBase.js
index 2f03180..84d2a63 100644
--- a/resources/js/PendingToastBase.js
+++ b/resources/js/PendingToastBase.js
@@ -58,6 +58,11 @@ export class PendingToastBase {
   native({ ios = true, android = true } = {}) {
     return this.set("native", { ios: Boolean(ios), android: Boolean(android) });
   }
+  opacity(value = 0.8) {
+    if (!Number.isFinite(value))
+      throw new TypeError("opacity must be a finite number");
+    return this.set("opacity", Math.max(0, Math.min(1, value)));
+  }
   duration(value) {
     this.set("persistent", false);
     return this.set("duration", positiveInteger(value, "duration"));
@@ -74,7 +79,8 @@ export class PendingToastBase {
     return this.set("direction", oneOf(value, "direction"));
   }
   progress(value) {
-    if (!Number.isFinite(value)) throw new TypeError("progress must be a finite number");
+    if (!Number.isFinite(value))
+      throw new TypeError("progress must be a finite number");
     return this.set("progress", Math.max(0, Math.min(100, value)));
   }
   loading(enabled = true) {
diff --git a/resources/js/tests/toastkit.test.js b/resources/js/tests/toastkit.test.js
index 0e3a94d..b5668bf 100644
--- a/resources/js/tests/toastkit.test.js
+++ b/resources/js/tests/toastkit.test.js
@@ -106,6 +106,23 @@ test("native appearance can be changed through a sparse update", () => {
   assert.deepEqual(payload.changes, { native: { ios: false, android: true } });
 });
 
+test("opacity is opt-in, defaults to 0.8, preserves zero, and clamps", () => {
+  assert.equal("opacity" in Toast.success("Default").payload(), false);
+  assert.equal(Toast.success("Subtle").opacity().payload().opacity, 0.8);
+  assert.equal(Toast.success("Half").opacity(0.5).payload().opacity, 0.5);
+  assert.equal(Toast.success("Hidden").opacity(0).payload().opacity, 0);
+  assert.equal(Toast.success("Opaque").opacity(1).payload().opacity, 1);
+  assert.equal(Toast.success("Low").opacity(-1).payload().opacity, 0);
+  assert.equal(Toast.success("High").opacity(2).payload().opacity, 1);
+});
+
+test("opacity is sparse in updates and omitted updates do not reset it", () => {
+  assert.deepEqual(Toast.update("toast").opacity(0).payload().changes, { opacity: 0 });
+  assert.deepEqual(Toast.update("toast").message("Almost finished").payload().changes, {
+    message: "Almost finished",
+  });
+});
+
 test("new animations, direction, progress and loading are set", () => {
   for (const animation of ["snap", "pop", "reveal", "bounce"])
     assert.equal(Toast.make("x").animation(animation).payload().animation, animation);
diff --git a/src/Concerns/ConfiguresToast.php b/src/Concerns/ConfiguresToast.php
index 66fdb39..6ea92e0 100644
--- a/src/Concerns/ConfiguresToast.php
+++ b/src/Concerns/ConfiguresToast.php
@@ -97,6 +97,11 @@ public function native(bool $ios = true, bool $android = true): static
         return $this->put('native', ['ios' => $ios, 'android' => $android]);
     }
 
+    public function opacity(float $opacity = 0.8): static
+    {
+        return $this->put('opacity', max(0.0, min(1.0, $opacity)));
+    }
+
     public function duration(int $milliseconds): static
     {
         if ($milliseconds <= 0) throw new InvalidToastConfigurationException('Toast duration must be greater than zero milliseconds.');
diff --git a/tests/Unit/OpacityTest.php b/tests/Unit/OpacityTest.php
new file mode 100644
index 0000000..4e969df
--- /dev/null
+++ b/tests/Unit/OpacityTest.php
@@ -0,0 +1,51 @@
+<?php
+
+use Victorycodedev\ToastKit\PendingToast;
+
+it('omits opacity unless explicitly configured', function () {
+    $payload = $this->kit->success('Saved')->payload();
+
+    expect($payload)->not->toHaveKey('opacity');
+});
+
+it('uses 0.8 when opacity is called without an argument', function () {
+    $this->kit->success('Saved')->opacity()->show();
+
+    expect($this->calls[0][1]['opacity'])->toBe(0.8);
+});
+
+it('preserves explicit opacity values', function (float $opacity) {
+    $this->kit->success('Saved')->opacity($opacity)->show();
+
+    expect($this->calls[0][1]['opacity'])->toBe($opacity);
+})->with([0.0, 0.5, 0.65, 1.0]);
+
+it('clamps opacity to the supported range', function (float $input, float $expected) {
+    $this->kit->success('Saved')->opacity($input)->show();
+
+    expect($this->calls[0][1]['opacity'])->toBe($expected);
+})->with([
+    'below zero' => [-1.0, 0.0],
+    'above one' => [2.0, 1.0],
+]);
+
+it('sends opacity as a sparse update and preserves zero', function () {
+    $this->kit->update('toast')->opacity(0.0)->show();
+    $this->kit->update('toast')->message('Almost finished')->show();
+
+    expect($this->calls[0][1]['changes'])->toBe(['opacity' => 0.0])
+        ->and($this->calls[1][1]['changes'])->toBe(['message' => 'Almost finished']);
+});
+
+it('supports preset opacity and explicit per-toast overrides', function () {
+    $this->kit->definePreset('subtle', fn(PendingToast $toast) => $toast
+        ->opacity()
+        ->position('bottom')
+        ->animation('fade'));
+
+    $this->kit->preset('subtle')->message('Copied')->show();
+    $this->kit->preset('subtle')->message('Saved')->opacity(0.45)->show();
+
+    expect($this->calls[0][1]['opacity'])->toBe(0.8)
+        ->and($this->calls[1][1]['opacity'])->toBe(0.45);
+});