diff --git a/tests/Encoders/FileExtensionEncoderTest.php b/tests/Encoders/FileExtensionEncoderTest.php
new file mode 100644
index 00000000..e46ad337
--- /dev/null
+++ b/tests/Encoders/FileExtensionEncoderTest.php
@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests\Encoders;
+
+use Intervention\Image\Encoders\AvifEncoder;
+use Intervention\Image\Encoders\BmpEncoder;
+use Intervention\Image\Encoders\FileExtensionEncoder;
+use Intervention\Image\Encoders\GifEncoder;
+use Intervention\Image\Encoders\HeicEncoder;
+use Intervention\Image\Encoders\Jpeg2000Encoder;
+use Intervention\Image\Encoders\JpegEncoder;
+use Intervention\Image\Encoders\PngEncoder;
+use Intervention\Image\Encoders\TiffEncoder;
+use Intervention\Image\Encoders\WebpEncoder;
+use Intervention\Image\Exceptions\EncoderException;
+use Intervention\Image\Tests\TestCase;
+use Mockery;
+
+class FileExtensionEncoderTest extends TestCase
+{
+    public function testEncoderByFileExtension(): void
+    {
+        $encoder = Mockery::mock(FileExtensionEncoder::class);
+
+        $this->assertInstanceOf(
+            WebpEncoder::class,
+            $encoder->encoderByFileExtension('webp')
+        );
+
+        $this->assertInstanceOf(
+            AvifEncoder::class,
+            $encoder->encoderByFileExtension('avif')
+        );
+
+        $this->assertInstanceOf(
+            JpegEncoder::class,
+            $encoder->encoderByFileExtension('jpeg')
+        );
+
+        $this->assertInstanceOf(
+            BmpEncoder::class,
+            $encoder->encoderByFileExtension('bmp')
+        );
+
+        $this->assertInstanceOf(
+            GifEncoder::class,
+            $encoder->encoderByFileExtension('gif')
+        );
+
+        $this->assertInstanceOf(
+            PngEncoder::class,
+            $encoder->encoderByFileExtension('png')
+        );
+
+        $this->assertInstanceOf(
+            TiffEncoder::class,
+            $encoder->encoderByFileExtension('tiff')
+        );
+
+        $this->assertInstanceOf(
+            Jpeg2000Encoder::class,
+            $encoder->encoderByFileExtension('jp2')
+        );
+
+        $this->assertInstanceOf(
+            HeicEncoder::class,
+            $encoder->encoderByFileExtension('heic')
+        );
+    }
+
+    public function testEncoderByFileExtensionUnknown(): void
+    {
+        $encoder = Mockery::mock(FileExtensionEncoder::class);
+        $this->expectException(EncoderException::class);
+        $encoder->encoderByFileExtension('test');
+    }
+}