diff --git a/application/config/mimes.php b/application/config/mimes.php
index b2e989fea9e..5b45f16bf55 100644
--- a/application/config/mimes.php
+++ b/application/config/mimes.php
@@ -90,6 +90,8 @@
 	'tif'	=>	'image/tiff',
 	'heic' 	=>	'image/heic',
 	'heif' 	=>	'image/heif',
+	'avif' 	=>	'image/avif',
+	'webp' 	=>	'image/webp',
 	'css'	=>	array('text/css', 'text/plain'),
 	'html'	=>	array('text/html', 'text/plain'),
 	'htm'	=>	array('text/html', 'text/plain'),
diff --git a/system/language/english/imglib_lang.php b/system/language/english/imglib_lang.php
index b0a80a5d063..1fc34df15f9 100644
--- a/system/language/english/imglib_lang.php
+++ b/system/language/english/imglib_lang.php
@@ -46,6 +46,8 @@
 $lang['imglib_jpg_not_supported'] = 'JPG images are not supported.';
 $lang['imglib_png_not_supported'] = 'PNG images are not supported.';
 $lang['imglib_webp_not_supported'] = 'WEBP images are not supported.';
+$lang['imglib_avif_not_supported'] = 'AVIF images are not supported.';
+$lang['imglib_webp_not_supported'] = 'WEBP images are not supported.';
 $lang['imglib_jpg_or_png_required'] = 'The image resize protocol specified in your preferences only works with JPEG or PNG image types.';
 $lang['imglib_copy_error'] = 'An error was encountered while attempting to replace the file. Please make sure your file directory is writable.';
 $lang['imglib_rotate_unsupported'] = 'Image rotation does not appear to be supported by your server.';
diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index 4e5fc7be6fc..8f4869b700e 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -566,7 +566,7 @@ public function initialize($props = array())
 		else
 		{
 			// Is there a file name?
-			if ( ! preg_match('#\.(jpg|jpeg|gif|png)$#i', $this->new_image))
+			if ( ! preg_match('#\.(jpe?g|gif|png|webp|avif)$#i', $this->new_image))
 			{
 				$this->dest_image  = $this->source_image;
 				$this->dest_folder = $this->new_image;
@@ -814,7 +814,8 @@ public function image_process_gd($action = 'resize')
 
 		$dst_img = $create($this->width, $this->height);
 
-		if ($this->image_type === 3) // png we can actually preserve transparency
+		// We can preserve transparency for PNG, WEBP, AVIF images
+		if (in_array($this->image_type, [IMAGETYPE_PNG, IMAGETYPE_WEBP, IMAGETYPE_AVIF], true))
 		{
 			imagealphablending($dst_img, FALSE);
 			imagesavealpha($dst_img, TRUE);
@@ -935,22 +936,26 @@ public function image_process_netpbm($action = 'resize')
 		// Build the resizing command
 		switch ($this->image_type)
 		{
-			case 1 :
+			case IMAGETYPE_GIF :
 				$cmd_in		= 'giftopnm';
 				$cmd_out	= 'ppmtogif';
 				break;
-			case 2 :
+			case IMAGETYPE_JPEG :
 				$cmd_in		= 'jpegtopnm';
 				$cmd_out	= 'ppmtojpeg';
 				break;
-			case 3 :
+			case IMAGETYPE_PNG :
 				$cmd_in		= 'pngtopnm';
 				$cmd_out	= 'ppmtopng';
 				break;
-			case 18 :
+			/*case IMAGETYPE_WEBP :
 				$cmd_in		= 'webptopnm';
 				$cmd_out	= 'ppmtowebp';
 				break;
+			case IMAGETYPE_AVIF :
+				$cmd_in		= 'webptopnm';
+				$cmd_out	= 'ppmtowebp';
+				break;*/
 		}
 
 		if ($action === 'crop')
@@ -1234,8 +1239,8 @@ public function overlay_watermark()
 			imagecopymerge($src_img, $wm_img, $x_axis, $y_axis, 0, 0, $wm_width, $wm_height, $this->wm_opacity);
 		}
 
-		// We can preserve transparency for PNG images
-		if ($this->image_type === 3)
+		// We can preserve transparency for PNG, WEBP, AVIF images
+		if (in_array($this->image_type, [IMAGETYPE_PNG, IMAGETYPE_WEBP, IMAGETYPE_AVIF], true))
 		{
 			imagealphablending($src_img, FALSE);
 			imagesavealpha($src_img, TRUE);
@@ -1405,8 +1410,8 @@ public function text_watermark()
 			imagestring($src_img, $this->wm_font_size, $x_axis, $y_axis, $this->wm_text, $txt_color);
 		}
 
-		// We can preserve transparency for PNG images
-		if ($this->image_type === 3)
+		// We can preserve transparency for PNG, WEBP, AVIF images
+		if (in_array($this->image_type, [IMAGETYPE_PNG, IMAGETYPE_WEBP, IMAGETYPE_AVIF], true))
 		{
 			imagealphablending($src_img, FALSE);
 			imagesavealpha($src_img, TRUE);
@@ -1453,7 +1458,7 @@ public function image_create_gd($path = '', $image_type = '')
 
 		switch ($image_type)
 		{
-			case 1:
+			case IMAGETYPE_GIF:
 				if ( ! function_exists('imagecreatefromgif'))
 				{
 					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_gif_not_supported'));
@@ -1461,7 +1466,7 @@ public function image_create_gd($path = '', $image_type = '')
 				}
 
 				return imagecreatefromgif($path);
-			case 2:
+			case IMAGETYPE_JPEG:
 				if ( ! function_exists('imagecreatefromjpeg'))
 				{
 					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_jpg_not_supported'));
@@ -1469,7 +1474,7 @@ public function image_create_gd($path = '', $image_type = '')
 				}
 
 				return imagecreatefromjpeg($path);
-			case 3:
+			case IMAGETYPE_PNG:
 				if ( ! function_exists('imagecreatefrompng'))
 				{
 					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_png_not_supported'));
@@ -1477,7 +1482,7 @@ public function image_create_gd($path = '', $image_type = '')
 				}
 
 				return imagecreatefrompng($path);
-			case 18:
+			case IMAGETYPE_WEBP:
 				if ( ! function_exists('imagecreatefromwebp'))
 				{
 					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_webp_not_supported'));
@@ -1485,6 +1490,14 @@ public function image_create_gd($path = '', $image_type = '')
 				}
 
 				return imagecreatefromwebp($path);
+			case IMAGETYPE_AVIF:
+				if ( ! function_exists('imagecreatefromavif'))
+				{
+					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_avif_not_supported'));
+					return FALSE;
+				}
+
+				return imagecreatefromavif($path);
 			default:
 				$this->set_error(array('imglib_unsupported_imagecreate'));
 				return FALSE;
@@ -1506,7 +1519,7 @@ public function image_save_gd($resource)
 	{
 		switch ($this->image_type)
 		{
-			case 1:
+			case IMAGETYPE_GIF:
 				if ( ! function_exists('imagegif'))
 				{
 					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_gif_not_supported'));
@@ -1519,7 +1532,7 @@ public function image_save_gd($resource)
 					return FALSE;
 				}
 			break;
-			case 2:
+			case IMAGETYPE_JPEG :
 				if ( ! function_exists('imagejpeg'))
 				{
 					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_jpg_not_supported'));
@@ -1532,7 +1545,7 @@ public function image_save_gd($resource)
 					return FALSE;
 				}
 			break;
-			case 3:
+			case IMAGETYPE_PNG:
 				if ( ! function_exists('imagepng'))
 				{
 					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_png_not_supported'));
@@ -1545,7 +1558,7 @@ public function image_save_gd($resource)
 					return FALSE;
 				}
 			break;
-			case 18:
+			case IMAGETYPE_WEBP:
 				if ( ! function_exists('imagewebp'))
 				{
 					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_webp_not_supported'));
@@ -1558,6 +1571,19 @@ public function image_save_gd($resource)
 					return FALSE;
 				}
 			break;
+			case IMAGETYPE_AVIF:
+				if ( ! function_exists('imageavif'))
+				{
+					$this->set_error(array('imglib_unsupported_imagecreate', 'imglib_avif_not_supported'));
+					return FALSE;
+				}
+
+				if ( ! @imageavif($resource, $this->full_dst_path))
+				{
+					$this->set_error('imglib_save_failed');
+					return FALSE;
+				}
+			break;
 			default:
 				$this->set_error(array('imglib_unsupported_imagecreate'));
 				return FALSE;
@@ -1593,13 +1619,15 @@ public function image_display_gd($resource)
 
 		switch ($this->image_type)
 		{
-			case 1	:	imagegif($resource);
+			case IMAGETYPE_GIF	:	imagegif($resource);
+				break;
+			case IMAGETYPE_JPEG	:	imagejpeg($resource, NULL, $this->quality);
 				break;
-			case 2	:	imagejpeg($resource, NULL, $this->quality);
+			case IMAGETYPE_PNG	:	imagepng($resource);
 				break;
-			case 3	:	imagepng($resource);
+			case IMAGETYPE_WEBP	:	imagewebp($resource);
 				break;
-			case 18	:	imagewebp($resource);
+			case IMAGETYPE_AVIF	:	imageavif($resource);
 				break;
 			default:	echo 'Unable to display the image';
 				break;
@@ -1695,7 +1723,7 @@ public function get_image_properties($path = '', $return = FALSE)
 			return FALSE;
 		}
 
-		$types = array(1 => 'gif', 2 => 'jpeg', 3 => 'png');
+		$types = array(IMAGETYPE_GIF => 'gif', IMAGETYPE_JPEG => 'jpeg', IMAGETYPE_PNG => 'png', IMAGETYPE_WEBP => 'webp', IMAGETYPE_AVIF => 'avif');
 		$mime = isset($types[$vals[2]]) ? 'image/'.$types[$vals[2]] : 'image/jpg';
 
 		if ($return === TRUE)
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index 168211a9144..383efcb4bdb 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -815,7 +815,7 @@ public function set_image_properties($path = '')
 		{
 			if (FALSE !== ($D = @getimagesize($path)))
 			{
-				$types = array(1 => 'gif', 2 => 'jpeg', 3 => 'png');
+				$types = array(IMAGETYPE_GIF => 'gif', IMAGETYPE_JPEG => 'jpeg', IMAGETYPE_PNG => 'png', IMAGETYPE_WEBP => 'webp', IMAGETYPE_AVIF => 'avif');
 
 				$this->image_width	= $D[0];
 				$this->image_height	= $D[1];