diff --git a/src/Tracer/ErrorHandler.php b/src/Tracer/ErrorHandler.php
index 5c4ed3b85..08fdf590f 100644
--- a/src/Tracer/ErrorHandler.php
+++ b/src/Tracer/ErrorHandler.php
@@ -17,13 +17,13 @@
 namespace Quantum\Tracer;
 
 use Quantum\Storage\Contracts\LocalFilesystemAdapterInterface;
+use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Console\Output\ConsoleOutput;
 use Quantum\Renderer\Exceptions\RendererException;
 use Quantum\Config\Exceptions\ConfigException;
 use Quantum\App\Exceptions\BaseException;
 use Quantum\View\Factories\ViewFactory;
 use Quantum\Di\Exceptions\DiException;
-use DebugBar\DebugBarException;
 use Quantum\Logger\Logger;
 use ReflectionException;
 use Psr\Log\LogLevel;
@@ -63,6 +63,7 @@ class ErrorHandler
     ];
 
     private ?Logger $logger = null;
+    private ?OutputInterface $cliOutput = null;
 
     private function __clone()
     {
@@ -77,6 +78,11 @@ public function setup(Logger $logger): void
         set_exception_handler([$this, 'handleException']);
     }
 
+    public function setCliOutput(OutputInterface $output): void
+    {
+        $this->cliOutput = $output;
+    }
+
     /**
      * @throws ErrorException
      */
@@ -90,7 +96,7 @@ public function handleError(int $severity, string $message, string $file, int $l
     }
 
     /**
-     * @throws ConfigException|RendererException|DebugBarException|DiException|BaseException|ReflectionException
+     * @throws ConfigException|RendererException|DiException|BaseException|ReflectionException
      */
     public function handleException(Throwable $throwable): void
     {
@@ -103,7 +109,7 @@ public function handleException(Throwable $throwable): void
 
     private function handleCliException(Throwable $throwable): void
     {
-        $output = new ConsoleOutput();
+        $output = $this->cliOutput ?? new ConsoleOutput();
         $output->writeln('<error>' . $throwable->getMessage() . '</error>');
     }
 
diff --git a/tests/Unit/Tracer/ErrorHandlerTest.php b/tests/Unit/Tracer/ErrorHandlerTest.php
index deafb5055..bd03fe966 100644
--- a/tests/Unit/Tracer/ErrorHandlerTest.php
+++ b/tests/Unit/Tracer/ErrorHandlerTest.php
@@ -2,10 +2,19 @@
 
 namespace Quantum\Tests\Unit\Tracer;
 
+use Quantum\Storage\Factories\FileSystemFactory;
+use Quantum\Storage\Contracts\FilesystemAdapterInterface;
+use Quantum\Storage\FileSystem;
 use Quantum\Tests\Unit\AppTestCase;
 use Quantum\Tracer\ErrorHandler;
+use Quantum\Di\Di;
 use Quantum\Logger\Logger;
+use Symfony\Component\Console\Output\BufferedOutput;
+use ReflectionException;
+use ReflectionMethod;
 use ErrorException;
+use ParseError;
+use Exception;
 use Mockery;
 
 class ErrorHandlerTest extends AppTestCase
@@ -92,4 +101,250 @@ public function testErrorTypesConstant(): void
         $this->assertEquals('notice', ErrorHandler::ERROR_TYPES[E_NOTICE]);
         $this->assertEquals('error', ErrorHandler::ERROR_TYPES[E_PARSE]);
     }
+
+    public function testHandleExceptionCliWritesExceptionMessage(): void
+    {
+        $output = new BufferedOutput();
+        $this->errorHandler->setCliOutput($output);
+
+        $this->errorHandler->handleException(new Exception('CLI failure'));
+
+        $this->assertStringContainsString('CLI failure', $output->fetch());
+    }
+
+    public function testHandleWebExceptionInDebugModeRendersTraceView(): void
+    {
+        config()->set('app.debug', true);
+
+        $exception = new Exception('Web debug failure');
+
+        ob_start();
+        $this->invokePrivateMethod('handleWebException', [$exception]);
+        ob_get_clean();
+
+        $content = response()->getContent();
+        $this->assertStringContainsString('TRACE VIEW', $content);
+        $this->assertStringContainsString('Error :: Web debug failure', $content);
+    }
+
+    public function testHandleWebExceptionInProductionModeLogsAndRenders500(): void
+    {
+        config()->set('app.debug', false);
+
+        $logger = Mockery::mock(Logger::class);
+        $logger->shouldReceive('warning')
+            ->once()
+            ->with('Web production warning', Mockery::on(function (array $context): bool {
+                return array_key_exists('trace', $context) && is_string($context['trace']);
+            }));
+
+        $this->setPrivateProperty($this->errorHandler, 'logger', $logger);
+
+        $exception = new ErrorException('Web production warning', 0, E_WARNING, __FILE__, __LINE__);
+
+        ob_start();
+        $this->invokePrivateMethod('handleWebException', [$exception]);
+        ob_get_clean();
+
+        $content = response()->getContent();
+        $this->assertStringContainsString('ERROR 500 VIEW', $content);
+    }
+
+    public function testLogErrorReturnsEarlyWhenLoggerIsNull(): void
+    {
+        $this->setPrivateProperty($this->errorHandler, 'logger', null);
+
+        $this->invokePrivateMethod('logError', [new Exception('No logger'), 'error']);
+
+        $this->assertTrue(true);
+    }
+
+    public function testLogErrorFallsBackToErrorMethodForUnknownLevel(): void
+    {
+        $logger = Mockery::mock(Logger::class);
+        $logger->shouldReceive('error')
+            ->once()
+            ->with('Unknown level message', Mockery::type('array'));
+
+        $this->setPrivateProperty($this->errorHandler, 'logger', $logger);
+
+        $this->invokePrivateMethod('logError', [new Exception('Unknown level message'), 'not_existing_level']);
+
+        $this->assertTrue(true);
+    }
+
+    public function testComposeStackTraceSkipsHandlerClassEntriesAndBuildsCodeSnippets(): void
+    {
+        $sourceFile = PROJECT_ROOT . DS . 'shared' . DS . 'trace-source.php';
+        $this->createFile($sourceFile, "<?php\nline1\nline2\nline3\nline4\nline5\n");
+
+        try {
+            $throwable = new Exception('trace');
+            $throwableProperty = new \ReflectionProperty(Exception::class, 'file');
+            $throwableProperty->setAccessible(true);
+            $throwableProperty->setValue($throwable, $sourceFile);
+
+            $lineProperty = new \ReflectionProperty(Exception::class, 'line');
+            $lineProperty->setAccessible(true);
+            $lineProperty->setValue($throwable, 3);
+
+            $traceProperty = new \ReflectionProperty(Exception::class, 'trace');
+            $traceProperty->setAccessible(true);
+            $traceProperty->setValue($throwable, [
+                ['class' => ErrorHandler::class, 'file' => $sourceFile, 'line' => 2],
+                ['class' => 'ExternalClass', 'file' => $sourceFile, 'line' => 4],
+                ['class' => 'NoFileClass'],
+            ]);
+
+            $trace = $this->invokePrivateMethod('composeStackTrace', [$throwable]);
+
+            $this->assertCount(2, $trace);
+            $this->assertSame($sourceFile, $trace[0]['file']);
+            $this->assertStringContainsString('<ol start="1">', $trace[0]['code']);
+            $this->assertStringContainsString('class="error-line"', $trace[0]['code']);
+            $this->assertSame($sourceFile, $trace[1]['file']);
+            $this->assertStringContainsString('class="switch-line"', $trace[1]['code']);
+        } finally {
+            $this->removeFile($sourceFile);
+        }
+    }
+
+    public function testGetSourceCodeReturnsEmptyStringForNonLocalAdapter(): void
+    {
+        $adapter = new class () implements FilesystemAdapterInterface {
+            public function makeDirectory(string $dirname, ?string $parentId = null): bool
+            {
+                return false;
+            }
+            public function removeDirectory(string $dirname): bool
+            {
+                return false;
+            }
+            public function get(string $filename)
+            {
+                return false;
+            }
+            public function put(string $filename, $content, ?string $parentId = null)
+            {
+                return false;
+            }
+            public function append(string $filename, $content)
+            {
+                return false;
+            }
+            public function rename(string $oldName, string $newName): bool
+            {
+                return false;
+            }
+            public function copy(string $source, string $dest): bool
+            {
+                return false;
+            }
+            public function exists(string $filename): bool
+            {
+                return false;
+            }
+            public function size(string $filename)
+            {
+                return false;
+            }
+            public function lastModified(string $filename)
+            {
+                return false;
+            }
+            public function remove(string $filename): bool
+            {
+                return false;
+            }
+            public function isFile(string $filename): bool
+            {
+                return false;
+            }
+            public function isDirectory(string $dirname): bool
+            {
+                return false;
+            }
+            public function listDirectory(string $dirname)
+            {
+                return false;
+            }
+        };
+
+        $factory = Di::get(FileSystemFactory::class);
+        $instancesProperty = new \ReflectionProperty(FileSystemFactory::class, 'instances');
+        $instancesProperty->setAccessible(true);
+        $originalInstances = $instancesProperty->getValue($factory);
+
+        try {
+            $instancesProperty->setValue($factory, ['local' => new FileSystem($adapter)]);
+
+            $code = $this->invokePrivateMethod('getSourceCode', [__FILE__, 10, 'error-line']);
+
+            $this->assertSame('', $code);
+        } finally {
+            $instancesProperty->setValue($factory, $originalInstances);
+        }
+    }
+
+    public function testGetSourceCodeBuildsOrderedListForLocalAdapter(): void
+    {
+        $file = PROJECT_ROOT . DS . 'shared' . DS . 'source-code.php';
+        $this->createFile($file, "<?php\nA\nB\nC\nD\nE\nF\nG\n");
+
+        try {
+            $code = $this->invokePrivateMethod('getSourceCode', [$file, 5, 'error-line']);
+
+            $this->assertStringContainsString('<ol start="1">', $code);
+            $this->assertStringContainsString('class="error-line"', $code);
+            $this->assertStringContainsString('<pre>C</pre>', $code);
+        } finally {
+            $this->removeFile($file);
+        }
+    }
+
+    public function testFormatLineItemEscapesHtmlAndAppliesHighlightClass(): void
+    {
+        $html = $this->invokePrivateMethod('formatLineItem', [5, '<div class="x">A&B</div>', 5, 'switch-line']);
+        $plain = $this->invokePrivateMethod('formatLineItem', [4, 'plain', 5, 'switch-line']);
+
+        $this->assertStringContainsString('class="switch-line"', $html);
+        $this->assertStringContainsString('&lt;div class=&quot;x&quot;&gt;A&amp;B&lt;/div&gt;', $html);
+        $this->assertStringNotContainsString('class="switch-line"', $plain);
+    }
+
+    /**
+     * @dataProvider errorTypeProvider
+     */
+    public function testGetErrorTypeMappings(\Throwable $throwable, string $expected): void
+    {
+        $type = $this->invokePrivateMethod('getErrorType', [$throwable]);
+
+        $this->assertSame($expected, $type);
+    }
+
+    /**
+     * @return array<string, array{0: \Throwable, 1: string}>
+     */
+    public function errorTypeProvider(): array
+    {
+        return [
+            'mapped-error-exception' => [new ErrorException('x', 0, E_WARNING), 'warning'],
+            'unmapped-error-exception' => [new ErrorException('x', 0, E_USER_DEPRECATED), 'error'],
+            'parse-error' => [new ParseError('bad syntax'), 'critical'],
+            'reflection-exception' => [new ReflectionException('reflection failed'), 'warning'],
+            'generic-exception' => [new Exception('unknown'), 'error'],
+        ];
+    }
+
+    /**
+     * @param array<int, mixed> $args
+     * @return mixed
+     */
+    private function invokePrivateMethod(string $method, array $args = [])
+    {
+        $reflectionMethod = new ReflectionMethod($this->errorHandler, $method);
+        $reflectionMethod->setAccessible(true);
+
+        return $reflectionMethod->invokeArgs($this->errorHandler, $args);
+    }
 }
diff --git a/tests/_root/shared/views/errors/500.php b/tests/_root/shared/views/errors/500.php
new file mode 100644
index 000000000..72bcdeaa8
--- /dev/null
+++ b/tests/_root/shared/views/errors/500.php
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <title>Error Page 500</title>
+    </head>
+
+    <body>
+
+        <main>
+            <h1>500</h1>
+            <h3>ERROR 500 VIEW</h3>
+        </main>
+
+    </body>
+</html>
diff --git a/tests/_root/shared/views/errors/trace.php b/tests/_root/shared/views/errors/trace.php
new file mode 100644
index 000000000..d962d69d7
--- /dev/null
+++ b/tests/_root/shared/views/errors/trace.php
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <title>Error Trace</title>
+    </head>
+
+    <body>
+
+        <main>
+            <h1>TRACE VIEW</h1>
+            <h3><?= $severity ?> :: <?= $errorMessage ?></h3>
+            <div><?= count($stackTrace) ?></div>
+        </main>
+
+    </body>
+</html>