diff --git a/docs/guide/deferred-props.md b/docs/guide/deferred-props.md
index 9db7eb63..7e4a3a29 100644
--- a/docs/guide/deferred-props.md
+++ b/docs/guide/deferred-props.md
@@ -39,6 +39,10 @@ end
 
 In the example above, the `teams`, `projects`, and `tasks` props will be fetched in one request, while the `permissions` prop will be fetched in a separate request in parallel. Group names are arbitrary strings and can be anything you choose.
 
+### Combining with mergeable props
+
+Deferred props can be combined with mergeable props. You can learn more about this feature in the [Merging props](/guide/merging-props) section.
+
 ## Client side
 
 On the client side, Inertia provides the `Deferred` component to help you manage deferred props. This component will automatically wait for the specified deferred props to be available before rendering its children.
diff --git a/docs/guide/merging-props.md b/docs/guide/merging-props.md
index df843442..172aa54b 100644
--- a/docs/guide/merging-props.md
+++ b/docs/guide/merging-props.md
@@ -26,6 +26,15 @@ class UsersController < ApplicationController
           records: records.as_json(...),
           pagy: pagy_metadata(pagy)
         }
+      },
+      # with match_on parameter for smart merging:
+      products: InertiaRails.merge(match_on: 'id') { Product.all.as_json(...) },
+      # nested objects with match_on:
+      categories: InertiaRails.deep_merge(match_on: %w[items.id tags.id]) {
+        {
+          items: Category.all.as_json(...),
+          tags: Tag.all.as_json(...)
+        }
       }
     }
   end
@@ -34,7 +43,14 @@ end
 
 On the client side, Inertia detects that this prop should be merged. If the prop returns an array, it will append the response to the current prop value. If it's an object, it will merge the response with the current prop value. If you have opted to `deepMerge`, Inertia ensures a deep merge of the entire structure.
 
-**Of note:** During the merging process, if the value is an array, the incoming items will be _appended_ to the existing array, not merged by index.
+### Smart merging with `match_on`
+
+By default, arrays are simply appended during merging. If you need to update specific items in an array or replace them based on a unique identifier, you can use the `match_on` parameter.
+
+The `match_on` parameter enables smart merging by specifying a field to match on when merging arrays of objects:
+
+- For `merge` with simple arrays, specify the object key to match on (e.g., `'id'`)
+- For `deep_merge` with nested structures, use dot notation to specify the path (e.g., `'items.id'`)
 
 You can also combine [deferred props](/guide/deferred-props) with mergeable props to defer the loading of the prop and ultimately mark it as mergeable once it's loaded.
 
@@ -54,6 +70,15 @@ class UsersController < ApplicationController
           records: records.as_json(...),
           pagy: pagy_metadata(pagy)
         }
+      },
+      # with match_on parameter:
+      products: InertiaRails.defer(merge: true, match_on: 'id') { products.as_json(...) },
+      # nested objects with match_on:
+      categories: InertiaRails.defer(deep_merge: true, match_on: %w[items.id tags.id]) {
+        {
+          items: Category.all.as_json(...),
+          tags: Tag.all.as_json(...)
+        }
       }
     }
   end
diff --git a/lib/inertia_rails/defer_prop.rb b/lib/inertia_rails/defer_prop.rb
index 2d486b51..ec85ac04 100644
--- a/lib/inertia_rails/defer_prop.rb
+++ b/lib/inertia_rails/defer_prop.rb
@@ -4,9 +4,9 @@ module InertiaRails
   class DeferProp < IgnoreOnFirstLoadProp
     DEFAULT_GROUP = 'default'
 
-    attr_reader :group
+    attr_reader :group, :match_on
 
-    def initialize(group: nil, merge: nil, deep_merge: nil, &block)
+    def initialize(group: nil, merge: nil, deep_merge: nil, match_on: nil, &block)
       raise ArgumentError, 'Cannot set both `deep_merge` and `merge` to true' if deep_merge && merge
 
       super(&block)
@@ -14,6 +14,7 @@ def initialize(group: nil, merge: nil, deep_merge: nil, &block)
       @group = group || DEFAULT_GROUP
       @merge = merge || deep_merge
       @deep_merge = deep_merge
+      @match_on = match_on.nil? ? nil : Array(match_on)
     end
 
     def merge?
diff --git a/lib/inertia_rails/generators/controller_template_base.rb b/lib/inertia_rails/generators/controller_template_base.rb
index 75d261b5..aa452646 100644
--- a/lib/inertia_rails/generators/controller_template_base.rb
+++ b/lib/inertia_rails/generators/controller_template_base.rb
@@ -11,7 +11,7 @@ class ControllerTemplateBase < Rails::Generators::NamedBase
                                         default: Helper.guess_the_default_framework
 
       class_option :typescript, type: :boolean, desc: 'Whether to use TypeScript',
-                                default: Helper.guess_typescript
+                                default: Helper.uses_typescript?
 
       argument :actions, type: :array, default: [], banner: 'action action'
 
diff --git a/lib/inertia_rails/generators/helper.rb b/lib/inertia_rails/generators/helper.rb
index fb37cdb9..51434c31 100644
--- a/lib/inertia_rails/generators/helper.rb
+++ b/lib/inertia_rails/generators/helper.rb
@@ -23,7 +23,7 @@ def guess_the_default_framework(package_json_path = DEFAULT_PACKAGE_PATH)
           end
         end
 
-        def guess_typescript
+        def uses_typescript?
           Rails.root.join('tsconfig.json').exist?
         end
 
diff --git a/lib/inertia_rails/inertia_rails.rb b/lib/inertia_rails/inertia_rails.rb
index d2fb961f..f06bf8b2 100644
--- a/lib/inertia_rails/inertia_rails.rb
+++ b/lib/inertia_rails/inertia_rails.rb
@@ -33,16 +33,16 @@ def always(&block)
       AlwaysProp.new(&block)
     end
 
-    def merge(&block)
-      MergeProp.new(&block)
+    def merge(match_on: nil, &block)
+      MergeProp.new(match_on: match_on, &block)
     end
 
-    def deep_merge(&block)
-      MergeProp.new(deep_merge: true, &block)
+    def deep_merge(match_on: nil, &block)
+      MergeProp.new(deep_merge: true, match_on: match_on, &block)
     end
 
-    def defer(group: nil, merge: nil, deep_merge: nil, &block)
-      DeferProp.new(group: group, merge: merge, deep_merge: deep_merge, &block)
+    def defer(group: nil, merge: nil, deep_merge: nil, match_on: nil, &block)
+      DeferProp.new(group: group, merge: merge, deep_merge: deep_merge, match_on: match_on, &block)
     end
   end
 end
diff --git a/lib/inertia_rails/merge_prop.rb b/lib/inertia_rails/merge_prop.rb
index a90352b2..639a1e95 100644
--- a/lib/inertia_rails/merge_prop.rb
+++ b/lib/inertia_rails/merge_prop.rb
@@ -2,9 +2,12 @@
 
 module InertiaRails
   class MergeProp < BaseProp
-    def initialize(deep_merge: false, &block)
+    attr_reader :match_on
+
+    def initialize(deep_merge: false, match_on: nil, &block)
       super(&block)
       @deep_merge = deep_merge
+      @match_on = match_on.nil? ? nil : Array(match_on)
     end
 
     def merge?
diff --git a/lib/inertia_rails/renderer.rb b/lib/inertia_rails/renderer.rb
index 1e1b2043..641ddeeb 100644
--- a/lib/inertia_rails/renderer.rb
+++ b/lib/inertia_rails/renderer.rb
@@ -106,14 +106,17 @@ def page
       deferred_props = deferred_props_keys
       default_page[:deferredProps] = deferred_props if deferred_props.present?
 
-      all_merge_props = merge_props_keys
-
-      deep_merge_props, merge_props = all_merge_props.partition do |key|
-        @props[key].deep_merge?
+      deep_merge_props, merge_props = all_merge_props.partition do |_key, prop|
+        prop.deep_merge?
       end
 
-      default_page[:mergeProps] = merge_props if merge_props.present?
-      default_page[:deepMergeProps] = deep_merge_props if deep_merge_props.present?
+      match_props_on = all_merge_props.filter_map do |key, prop|
+        prop.match_on.map { |ms| "#{key}.#{ms}" } if prop.match_on.present?
+      end.flatten
+
+      default_page[:mergeProps] = merge_props.map(&:first) if merge_props.present?
+      default_page[:deepMergeProps] = deep_merge_props.map(&:first) if deep_merge_props.present?
+      default_page[:matchPropsOn] = match_props_on if match_props_on.present?
 
       default_page
     end
@@ -147,9 +150,16 @@ def deferred_props_keys
       end
     end
 
-    def merge_props_keys
-      @props.each_with_object([]) do |(key, prop), result|
-        result << key if prop.try(:merge?) && reset_keys.exclude?(key)
+    def all_merge_props
+      @all_merge_props ||= @props.select do |key, prop|
+        next unless prop.try(:merge?)
+        next if reset_keys.include?(key)
+        next if rendering_partial_component? && (
+          (partial_keys.present? && partial_keys.exclude?(key.name)) ||
+            (partial_except_keys.present? && partial_except_keys.include?(key.name))
+        )
+
+        true
       end
     end
 
@@ -180,7 +190,7 @@ def resolve_component(component)
     def keep_prop?(prop, path)
       return true if prop.is_a?(AlwaysProp)
 
-      if rendering_partial_component?
+      if rendering_partial_component? && (partial_keys.present? || partial_except_keys.present?)
         path_with_prefixes = path_prefixes(path)
         return false if excluded_by_only_partial_keys?(path_with_prefixes)
         return false if excluded_by_except_partial_keys?(path_with_prefixes)
diff --git a/spec/dummy/app/controllers/inertia_render_test_controller.rb b/spec/dummy/app/controllers/inertia_render_test_controller.rb
index 4d5134be..85928972 100644
--- a/spec/dummy/app/controllers/inertia_render_test_controller.rb
+++ b/spec/dummy/app/controllers/inertia_render_test_controller.rb
@@ -106,10 +106,14 @@ def always_props
   def merge_props
     render inertia: 'TestComponent', props: {
       merge: InertiaRails.merge { 'merge prop' },
+      match_on: InertiaRails.merge(match_on: 'id') { [id: 1] },
       deep_merge: InertiaRails.deep_merge { { deep: 'merge prop' } },
+      deep_match_on: InertiaRails.deep_merge(match_on: 'deep.id') { { deep: [id: 1] } },
       regular: 'regular prop',
       deferred_merge: InertiaRails.defer(merge: true) { 'deferred and merge prop' },
+      deferred_match_on: InertiaRails.defer(merge: true, match_on: 'id') { [id: 1] },
       deferred_deep_merge: InertiaRails.defer(deep_merge: true) { { deep: 'deferred and merge prop' } },
+      deferred_deep_match_on: InertiaRails.defer(deep_merge: true, match_on: 'deep.id') { { deep: [id: 1] } },
       deferred: InertiaRails.defer { 'deferred' },
     }
   end
diff --git a/spec/inertia/rendering_spec.rb b/spec/inertia/rendering_spec.rb
index fa635b69..537cb5c3 100644
--- a/spec/inertia/rendering_spec.rb
+++ b/spec/inertia/rendering_spec.rb
@@ -530,30 +530,37 @@
     before { get merge_props_path, headers: headers }
 
     it 'returns non-optional props and meta on first load' do
-      expect(response.parsed_body['props']).to eq('merge' => 'merge prop', 'deep_merge' => { 'deep' => 'merge prop' },
-                                                  'regular' => 'regular prop')
-      expect(response.parsed_body['mergeProps']).to match_array(%w[merge deferred_merge])
-      expect(response.parsed_body['deepMergeProps']).to match_array(%w[deep_merge deferred_deep_merge])
-      expect(response.parsed_body['deferredProps']).to eq('default' => %w[deferred_merge deferred_deep_merge deferred])
+      expect(response.parsed_body['props']).to eq(
+        'merge' => 'merge prop', 'match_on' => [{ 'id' => 1 }],
+        'deep_merge' => { 'deep' => 'merge prop' }, 'deep_match_on' => { 'deep' => [{ 'id' => 1 }] },
+        'regular' => 'regular prop'
+      )
+      expect(response.parsed_body['mergeProps']).to match_array(%w[merge match_on deferred_merge deferred_match_on])
+      expect(response.parsed_body['deepMergeProps']).to match_array(%w[deep_merge deep_match_on deferred_deep_merge deferred_deep_match_on])
+      expect(response.parsed_body['deferredProps']).to eq('default' => %w[deferred_merge deferred_match_on deferred_deep_merge deferred_deep_match_on deferred])
+      expect(response.parsed_body['matchPropsOn']).to match_array(%w[deep_match_on.deep.id deferred_deep_match_on.deep.id deferred_match_on.id match_on.id])
     end
 
     context 'with a partial reload' do
       let(:headers) do
         {
           'X-Inertia' => true,
-          'X-Inertia-Partial-Data' => 'deferred_merge,deferred_deep_merge',
+          'X-Inertia-Partial-Data' => 'deferred_merge,deferred_deep_merge,deferred_deep_match_on,deferred_match_on',
           'X-Inertia-Partial-Component' => 'TestComponent',
         }
       end
 
-      it 'returns listed and merge props' do
+      it 'returns listed merge props' do
         expect(response.parsed_body['props']).to eq(
           'deferred_merge' => 'deferred and merge prop',
-          'deferred_deep_merge' => { 'deep' => 'deferred and merge prop' }
+          'deferred_deep_merge' => { 'deep' => 'deferred and merge prop' },
+          'deferred_deep_match_on' => { 'deep' => [{ 'id' => 1 }] },
+          'deferred_match_on' => [{ 'id' => 1 }]
         )
-        expect(response.parsed_body['mergeProps']).to match_array(%w[merge deferred_merge])
-        expect(response.parsed_body['deepMergeProps']).to match_array(%w[deep_merge deferred_deep_merge])
+        expect(response.parsed_body['mergeProps']).to match_array(%w[deferred_merge deferred_match_on])
+        expect(response.parsed_body['deepMergeProps']).to match_array(%w[deferred_deep_merge deferred_deep_match_on])
         expect(response.parsed_body['deferredProps']).to be_nil
+        expect(response.parsed_body['matchPropsOn']).to match_array(%w[deferred_deep_match_on.deep.id deferred_match_on.id])
       end
     end
 
@@ -567,13 +574,36 @@
         }
       end
 
-      it 'returns listed and merge props' do
+      it 'returns listed props' do
         expect(response.parsed_body['props']).to eq(
           'deferred_merge' => 'deferred and merge prop',
           'deferred_deep_merge' => { 'deep' => 'deferred and merge prop' }
         )
-        expect(response.parsed_body['mergeProps']).to match_array(%w[merge])
+        expect(response.parsed_body['mergeProps']).to be_nil
+        expect(response.parsed_body['deferredProps']).to be_nil
+        expect(response.parsed_body['matchPropsOn']).to be_nil
+      end
+    end
+
+    context 'with an except header' do
+      let(:headers) do
+        {
+          'X-Inertia' => true,
+          'X-Inertia-Partial-Data' => 'deferred_merge,deferred_deep_merge,deep_match_on',
+          'X-Inertia-Partial-Except' => 'deferred_merge',
+          'X-Inertia-Partial-Component' => 'TestComponent',
+        }
+      end
+
+      it 'returns only the excepted props' do
+        expect(response.parsed_body['props']).to eq(
+          'deferred_deep_merge' => { 'deep' => 'deferred and merge prop' },
+          'deep_match_on' => { 'deep' => [{ 'id' => 1 }] }
+        )
+        expect(response.parsed_body['mergeProps']).to be_nil
+        expect(response.parsed_body['deepMergeProps']).to match_array(%w[deferred_deep_merge deep_match_on])
         expect(response.parsed_body['deferredProps']).to be_nil
+        expect(response.parsed_body['matchPropsOn']).to match_array(%w[deep_match_on.deep.id])
       end
     end
   end