diff --git a/extensions/auto_encoding_detection.go b/extensions/auto_encoding_detection.go
deleted file mode 100644
index 9021a758..00000000
--- a/extensions/auto_encoding_detection.go
+++ /dev/null
@@ -1,32 +0,0 @@
-package extensions
-
-import (
-	"bufio"
-	"io"
-
-	"golang.org/x/net/html/charset"
-	"golang.org/x/text/encoding/htmlindex"
-)
-
-func detectContentCharset(body io.Reader) string {
-	r := bufio.NewReader(body)
-	if data, err := r.Peek(1024); err == nil {
-		if _, name, ok := charset.DetermineEncoding(data, ""); ok {
-			return name
-		}
-	}
-	return "utf-8"
-}
-func DecodeHTMLBody(body io.Reader, charset string) (io.Reader, error) {
-	if charset == "" {
-		charset = detectContentCharset(body)
-	}
-	e, err := htmlindex.Get(charset)
-	if err != nil {
-		return nil, err
-	}
-	if name, _ := htmlindex.Name(e); name != "utf-8" {
-		body = e.NewDecoder().Reader(body)
-	}
-	return body, nil
-}