diff --git a/autoload/fuzzyy/files.vim b/autoload/fuzzyy/files.vim
index 4c6bd7ec..47af52e6 100644
--- a/autoload/fuzzyy/files.vim
+++ b/autoload/fuzzyy/files.vim
@@ -109,10 +109,13 @@ def Preview(wid: number, opts: dict<any>)
         return
     endif
     var preview_bufnr = winbufnr(preview_wid)
-    var fileraw = readfile(path, '', 1000)
-    noautocmd call popup_settext(preview_wid, fileraw)
+    if selector.IsBinary(path)
+        noautocmd call popup_settext(preview_wid, 'Cannot preview binary file')
+    else
+        noautocmd call popup_settext(preview_wid, readfile(path, '', 1000))
+        win_execute(preview_wid, 'silent! doautocmd filetypedetect BufNewFile ' .. path)
+    endif
     win_execute(preview_wid, 'norm gg')
-    win_execute(preview_wid, 'silent! doautocmd filetypedetect BufNewFile ' .. path)
     noautocmd win_execute(preview_wid, 'silent! setlocal nospell nolist')
 enddef
 
diff --git a/autoload/fuzzyy/grep.vim b/autoload/fuzzyy/grep.vim
index a6d8a1ed..12a046da 100644
--- a/autoload/fuzzyy/grep.vim
+++ b/autoload/fuzzyy/grep.vim
@@ -315,8 +315,7 @@ def Preview(wid: number, opts: dict<any>)
 
     if path != last_path
         var preview_bufnr = winbufnr(preview_wid)
-        var fileraw = readfile(path)
-        noautocmd call popup_settext(preview_wid, fileraw)
+        noautocmd call popup_settext(preview_wid, readfile(path))
         win_execute(preview_wid, 'silent! doautocmd filetypedetect BufNewFile ' .. path)
         noautocmd win_execute(preview_wid, 'silent! setlocal nospell nolist')
     endif
diff --git a/autoload/fuzzyy/mru.vim b/autoload/fuzzyy/mru.vim
index 92bd2cd0..ec2cdaed 100644
--- a/autoload/fuzzyy/mru.vim
+++ b/autoload/fuzzyy/mru.vim
@@ -41,10 +41,13 @@ def Preview(wid: number, opts: dict<any>)
         return
     endif
     var preview_bufnr = winbufnr(preview_wid)
-    var fileraw = readfile(path)
-    noautocmd call popup_settext(preview_wid, fileraw)
+    if selector.IsBinary(path)
+        noautocmd call popup_settext(preview_wid, 'Cannot preview binary file')
+    else
+        noautocmd call popup_settext(preview_wid, readfile(path))
+        win_execute(preview_wid, 'silent! doautocmd filetypedetect BufNewFile ' .. path)
+    endif
     win_execute(preview_wid, 'norm gg')
-    win_execute(preview_wid, 'silent! doautocmd filetypedetect BufNewFile ' .. path)
     noautocmd win_execute(preview_wid, 'silent! setlocal nospell nolist')
 enddef
 
diff --git a/autoload/fuzzyy/utils/selector.vim b/autoload/fuzzyy/utils/selector.vim
index 07f3b837..b5571c21 100644
--- a/autoload/fuzzyy/utils/selector.vim
+++ b/autoload/fuzzyy/utils/selector.vim
@@ -92,6 +92,18 @@ export def GetRootDir(): string
   return getcwd()
 enddef
 
+export def IsBinary(path: string): bool
+    # NUL byte check for binary files, used to avoid showing preview
+    # Assumes a file encoding that does not allow NUL bytes, so will
+    # generate false positives for UTF-16 and UTF-32, but the preview
+    # window doesn't work for these encodings anyway, even with a BOM
+    var bytes = readblob(path, 0, 128)
+    for byte in bytes
+        if byte == 0 | return true | endif
+    endfor
+    return false
+enddef
+
 # Search pattern @pattern in a list of strings @li
 # if pattern is empty, return [li, []]
 # params: