diff --git a/doc/RenderAsString.md b/doc/RenderAsString.md
index 4396452..daf3323 100644
--- a/doc/RenderAsString.md
+++ b/doc/RenderAsString.md
@@ -19,16 +19,30 @@ Note that the leading question mark will never be included.
 
 ## Change renderer
 
-Remove numeric indices:
+### Remove numeric indices:
+This renderer will render indexed arrays as `foo[]=bar&foo[]=baz` instead of `foo[0]=bar&foo[1]=baz`.
+
 ```php
 use function BenTools\QueryString\withoutNumericIndices;
-$qs = $qs->withRenderer(
-    withoutNumericIndices()
-);
-print(urldecode((string) $qs)); // yummy[fruits][]=strawberries&yummy[fruits][]=raspberries
+
+$qs = $qs->withRenderer(withoutNumericIndices());
+print(urldecode((string) $qs));
 ```
 
-Or define it on a global scope for future QueryString objects:
+### Flat renderer
+This renderer will render indexed arrays as `foo=bar&foo=baz` instead of `foo[0]=bar&foo[1]=baz`.
+
+```php
+use function BenTools\QueryString\flat;
+
+$qs = $qs->withRenderer(flat());
+print(urldecode((string) $qs));
+```
+
+### Global setting
+
+You can define a default renderer on a global scope for future QueryString objects:
+
 ```php
 use BenTools\QueryString\QueryString;
 use function BenTools\QueryString\withoutNumericIndices;
diff --git a/src/Renderer/FlatRenderer.php b/src/Renderer/FlatRenderer.php
new file mode 100644
index 0000000..f2ffc80
--- /dev/null
+++ b/src/Renderer/FlatRenderer.php
@@ -0,0 +1,86 @@
+<?php
+
+namespace BenTools\QueryString\Renderer;
+
+use BenTools\QueryString\QueryString;
+
+final class FlatRenderer implements QueryStringRendererInterface
+{
+    /**
+     * @var NativeRenderer
+     */
+    private $renderer;
+
+    protected function __construct(QueryStringRendererInterface $renderer = null)
+    {
+        $this->renderer = $renderer;
+    }
+
+    public static function factory(QueryStringRendererInterface $renderer = null)
+    {
+        return new self($renderer ?? NativeRenderer::factory());
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function render(QueryString $queryString): string
+    {
+        $separator = $this->getSeparator() ?? ini_get('arg_separator.output');
+        $parts = [[]];
+
+        foreach ($queryString->getParams() as $key => $value) {
+            $parts[] = $this->getParts($key, $value);
+        }
+
+        return \implode($separator, \array_merge([], ...$parts));
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getEncoding(): int
+    {
+        return $this->renderer->getEncoding();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function withEncoding(int $encoding): QueryStringRendererInterface
+    {
+        return new self($this->renderer->withEncoding($encoding));
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getSeparator(): ?string
+    {
+        return $this->renderer->getSeparator();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function withSeparator(?string $separator): QueryStringRendererInterface
+    {
+        return new self($this->renderer->withSeparator($separator));
+    }
+
+    private function getParts($key, $value): array
+    {
+        if (\is_iterable($value)) {
+            $parts = [[]];
+            foreach ($value as $sub) {
+                $parts[] = $this->getParts($key, $sub);
+            }
+
+            return \array_merge([], ...$parts);
+        }
+
+        $encode = \PHP_QUERY_RFC1738 === $this->getEncoding() ? '\\urlencode' : '\\rawurlencode';
+
+        return [$key . '=' . \call_user_func($encode, $value)];
+    }
+}
diff --git a/src/functions.php b/src/functions.php
index ee62e0b..20414f2 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -4,6 +4,7 @@
 
 use BenTools\QueryString\Parser\QueryStringParserInterface;
 use BenTools\QueryString\Renderer\ArrayValuesNormalizerRenderer;
+use BenTools\QueryString\Renderer\FlatRenderer;
 use BenTools\QueryString\Renderer\QueryStringRendererInterface;
 
 /**
@@ -25,6 +26,15 @@ function withoutNumericIndices(QueryStringRendererInterface $renderer = null): A
     return ArrayValuesNormalizerRenderer::factory($renderer);
 }
 
+/**
+ * @param QueryStringRendererInterface|null $renderer
+ * @return FlatRenderer
+ */
+function flat(QueryStringRendererInterface $renderer = null): FlatRenderer
+{
+    return FlatRenderer::factory($renderer);
+}
+
 /**
  * @param string      $queryString
  * @param bool        $decodeKeys
diff --git a/tests/FlatRendererTest.php b/tests/FlatRendererTest.php
new file mode 100644
index 0000000..363a0f0
--- /dev/null
+++ b/tests/FlatRendererTest.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace BenTools\QueryString\Tests;
+
+use PHPUnit\Framework\TestCase;
+use function BenTools\QueryString\flat;
+use function BenTools\QueryString\query_string;
+
+class FlatRendererTest extends TestCase
+{
+    public function testRenderer()
+    {
+        $data = [
+            'foo' => 'bar',
+            'foos' => [
+                'bar',
+                'foo bar',
+            ],
+            'fruits' => [
+                'banana' => 'yellow',
+                'strawberry' => 'red',
+            ],
+        ];
+
+        $qs = query_string($data);
+        $renderer = flat();
+
+        $this->assertEquals('foo=bar&foos=bar&foos=foo%20bar&fruits=yellow&fruits=red', (string) $qs->withRenderer(
+            $renderer
+        ));
+
+        $this->assertEquals('foo=bar&foos=bar&foos=foo+bar&fruits=yellow&fruits=red', (string) $qs->withRenderer(
+            $renderer->withEncoding(PHP_QUERY_RFC1738)
+        ));
+
+        $this->assertEquals('foo=bar;foos=bar;foos=foo+bar;fruits=yellow;fruits=red', (string) $qs->withRenderer(
+            $renderer->withEncoding(PHP_QUERY_RFC1738)->withSeparator(';')
+        ));
+    }
+
+}