diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
new file mode 100644
index 0000000..6cd52b0
--- /dev/null
+++ b/.github/workflows/benchmark.yml
@@ -0,0 +1,113 @@
+# https://help.github.com/en/categories/automating-your-workflow-with-github-actions
+
+name: "Benchmark"
+
+on:
+  pull_request:
+
+jobs:
+  phpbench:
+    name: "Benchmark"
+
+    runs-on: ${{ matrix.operating-system }}
+
+    strategy:
+      matrix:
+        dependencies:
+          - "locked"
+        php-version:
+          - "8.2"
+        operating-system:
+          - "ubuntu-latest"
+
+    steps:
+      - name: "Install PHP"
+        uses: "shivammathur/setup-php@2.25.5"
+        with:
+          coverage: "pcov"
+          php-version: "${{ matrix.php-version }}"
+          ini-values: memory_limit=-1
+          extensions: pdo_sqlite
+
+      - name: "Checkout base"
+        uses: actions/checkout@v3
+        with:
+          ref: ${{ github.base_ref }}
+
+      - uses: ramsey/composer-install@2.2.0
+        with:
+          dependency-versions: ${{ matrix.dependencies }}
+
+      - name: "phpbench on base"
+        run: "vendor/bin/phpbench run tests/Benchmark --progress=none --report=default --tag=base"
+
+      - name: "Checkout"
+        uses: actions/checkout@v3
+        with:
+          clean: false
+
+      - uses: ramsey/composer-install@2.2.0
+        with:
+          dependency-versions: ${{ matrix.dependencies }}
+
+      - name: "phpbench diff"
+        run: "vendor/bin/phpbench run tests/Benchmark --progress=none --report=diff --ref=base > bench.txt"
+
+      - name: "Get Bench Result"
+        id: phpbench
+        run: |
+          echo 'BENCH_RESULT<<EOF' >> $GITHUB_ENV
+          cat bench.txt >> $GITHUB_ENV
+          echo 'EOF' >> $GITHUB_ENV
+
+      - uses: actions/github-script@v6
+        with:
+          script: |
+            // Get the existing comments.
+            const {data: comments} = await github.rest.issues.listComments({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.payload.number,
+            })
+
+            // Find any comment already made by the bot.                                                                                                    
+            const botComment = comments.find(comment => comment.user.id === 41898282)                                                                       
+            const commentBody = `
+            
+            Hello :wave:
+          
+            <details>
+            <summary>here is the most recent benchmark result:</summary>
+            
+            <p>
+
+            \`\`\`
+            ${{ env.BENCH_RESULT }}
+            \`\`\`
+
+            </p>            
+            </details>
+
+            This comment gets update everytime a new commit comes in!
+
+            `;
+
+            if (context.payload.pull_request.head.repo.full_name !== 'patchlevel/event-sourcing') {
+              console.log('Not attempting to write comment on PR from fork');
+            } else {
+              if (botComment) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: botComment.id,
+                  body: commentBody
+                })
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.payload.number,
+                  body: commentBody
+                })
+              }
+            }
diff --git a/Makefile b/Makefile
index d90b09d..a15b772 100644
--- a/Makefile
+++ b/Makefile
@@ -41,5 +41,15 @@ static: psalm phpstan phpcs-check
 
 test: phpunit                                                                   ## run tests
 
+.PHONY: benchmark
+benchmark: vendor                                                               ## run benchmarks
+	vendor/bin/phpbench run tests/Benchmark --report=default
+
+.PHONY: benchmark-diff-test
+benchmark-diff-test: vendor                                                          ## run benchmarks
+	vendor/bin/phpbench run tests/Benchmark --revs=1 --report=default --progress=none --tag=base
+	vendor/bin/phpbench run tests/Benchmark --revs=1 --report=diff --progress=none --ref=base
+
+
 .PHONY: dev
 dev: static test                                                                ## run dev tools
diff --git a/phpbench.json b/phpbench.json
new file mode 100644
index 0000000..729b39d
--- /dev/null
+++ b/phpbench.json
@@ -0,0 +1,54 @@
+{
+  "$schema":"./vendor/phpbench/phpbench/phpbench.schema.json",
+  "runner.bootstrap": "vendor/autoload.php",
+  "runner.file_pattern": "*Bench.php",
+  "report.generators": {
+    "diff": {
+      "generator": "component",
+      "partition": ["benchmark_name"],
+      "components": [
+        {
+          "component": "section",
+          "title": "{{ first(frame[\"benchmark_name\"]) }}",
+          "components": [
+            {
+              "component": "table_aggregate",
+              "partition": ["subject_name", "variant_name"],
+              "groups":
+              {
+                "time (kde mode)":
+                {
+                  "cols": ["time"]
+                },
+                "memory":
+                {
+                  "cols": ["memory"]
+                }
+              },
+              "row":
+              {
+                "subject": "first(partition[\"subject_name\"]) ~ \" (\" ~ first(partition[\"variant_name\"]) ~ \")\"",
+                "time":
+                {
+                  "type": "expand",
+                  "partition": "suite_tag",
+                  "cols":
+                  {
+                    "Tag: {{ key }}": "mode(partition[\"result_time_avg\"]) as time ~ ' (' ~ rstdev(partition['result_time_avg']) ~ ')'"
+                  }
+                },
+                "memory":
+                {
+                  "type": "expand",
+                  "partition": "suite_tag",
+                  "cols":
+                  {
+                    "Tag: {{ key }} ": "mode(partition[\"result_mem_peak\"]) as memory"
+                  }
+                }
+              }
+            }]
+        }]
+    }
+  }
+}
\ No newline at end of file
diff --git a/tests/Benchmark/Fixture/NameChanged.php b/tests/Benchmark/Fixture/NameChanged.php
new file mode 100644
index 0000000..13dcfb6
--- /dev/null
+++ b/tests/Benchmark/Fixture/NameChanged.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\Hydrator\Tests\Benchmark\Fixture;
+
+final class NameChanged
+{
+    public function __construct(
+        public string $name,
+    ) {
+    }
+}
diff --git a/tests/Benchmark/Fixture/ProfileCreated.php b/tests/Benchmark/Fixture/ProfileCreated.php
new file mode 100644
index 0000000..945b9bb
--- /dev/null
+++ b/tests/Benchmark/Fixture/ProfileCreated.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\Hydrator\Tests\Benchmark\Fixture;
+
+final class ProfileCreated
+{
+    public function __construct(
+        #[ProfileIdNormalizer]
+        public ProfileId $profileId,
+        public string $name,
+    ) {
+    }
+}
diff --git a/tests/Benchmark/Fixture/ProfileId.php b/tests/Benchmark/Fixture/ProfileId.php
new file mode 100644
index 0000000..f08a379
--- /dev/null
+++ b/tests/Benchmark/Fixture/ProfileId.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\Hydrator\Tests\Benchmark\Fixture;
+
+final class ProfileId
+{
+    private function __construct(
+        private string $id,
+    ) {
+    }
+
+    public static function fromString(string $id): self
+    {
+        return new self($id);
+    }
+
+    public function toString(): string
+    {
+        return $this->id;
+    }
+}
diff --git a/tests/Benchmark/Fixture/ProfileIdNormalizer.php b/tests/Benchmark/Fixture/ProfileIdNormalizer.php
new file mode 100644
index 0000000..f867ebf
--- /dev/null
+++ b/tests/Benchmark/Fixture/ProfileIdNormalizer.php
@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\Hydrator\Tests\Benchmark\Fixture;
+
+use Attribute;
+use InvalidArgumentException;
+use Patchlevel\Hydrator\Normalizer\Normalizer;
+
+use function is_string;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+final class ProfileIdNormalizer implements Normalizer
+{
+    public function normalize(mixed $value): string
+    {
+        if (!$value instanceof ProfileId) {
+            throw new InvalidArgumentException();
+        }
+
+        return $value->toString();
+    }
+
+    public function denormalize(mixed $value): ProfileId|null
+    {
+        if ($value === null) {
+            return null;
+        }
+
+        if (!is_string($value)) {
+            throw new InvalidArgumentException();
+        }
+
+        return ProfileId::fromString($value);
+    }
+}
diff --git a/tests/Benchmark/HydratorBench.php b/tests/Benchmark/HydratorBench.php
new file mode 100644
index 0000000..4e8ae69
--- /dev/null
+++ b/tests/Benchmark/HydratorBench.php
@@ -0,0 +1,88 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\Hydrator\Tests\Benchmark;
+
+use Patchlevel\Hydrator\Hydrator;
+use Patchlevel\Hydrator\MetadataHydrator;
+use Patchlevel\Hydrator\Tests\Benchmark\Fixture\ProfileCreated;
+use Patchlevel\Hydrator\Tests\Benchmark\Fixture\ProfileId;
+use PhpBench\Attributes as Bench;
+
+#[Bench\BeforeMethods('setUp')]
+final class HydratorBench
+{
+    private Hydrator $hydrator;
+
+    public function setUp(): void
+    {
+        $this->hydrator = new MetadataHydrator();
+
+        $object = $this->hydrator->hydrate(ProfileCreated::class, [
+            'profileId' => '1',
+            'name' => 'foo',
+        ]);
+
+        $this->hydrator->extract($object);
+    }
+
+    #[Bench\Revs(10)]
+    public function benchHydrate1Object(): void
+    {
+        $this->hydrator->hydrate(ProfileCreated::class, [
+            'profileId' => '1',
+            'name' => 'foo',
+        ]);
+    }
+
+    #[Bench\Revs(10)]
+    public function benchExtract1Object(): void
+    {
+        $object = new ProfileCreated(ProfileId::fromString('1'), 'foo');
+
+        $this->hydrator->extract($object);
+    }
+
+    #[Bench\Revs(10)]
+    public function benchHydrate1_000Objects(): void
+    {
+        for ($i = 0; $i < 1_000; $i++) {
+            $this->hydrator->hydrate(ProfileCreated::class, [
+                'profileId' => '1',
+                'name' => 'foo',
+            ]);
+        }
+    }
+
+    #[Bench\Revs(10)]
+    public function benchExtract1_000Objects(): void
+    {
+        $object = new ProfileCreated(ProfileId::fromString('1'), 'foo');
+
+        for ($i = 0; $i < 1_000; $i++) {
+            $this->hydrator->extract($object);
+        }
+    }
+
+    #[Bench\Revs(10)]
+    public function benchHydrate1_000_000Objects(): void
+    {
+        for ($i = 0; $i < 1_000_000; $i++) {
+            $this->hydrator->hydrate(ProfileCreated::class, [
+                'profileId' => '1',
+                'name' => 'foo',
+            ]);
+        }
+    }
+
+    #[Bench\Revs(10)]
+    public function benchExtract1_000_000Objects(): void
+    {
+        $object = new ProfileCreated(ProfileId::fromString('1'), 'foo');
+
+        for ($i = 0; $i < 1_000_000; $i++) {
+            $this->hydrator->extract($object);
+        }
+    }
+}