diff --git a/httpie/cli/argparser.py b/httpie/cli/argparser.py
index 9bf09b3b73..c2e6be2e3e 100644
--- a/httpie/cli/argparser.py
+++ b/httpie/cli/argparser.py
@@ -5,7 +5,7 @@
 import sys
 from argparse import RawDescriptionHelpFormatter
 from textwrap import dedent
-from urllib.parse import urlsplit
+from urllib.parse import urlsplit, unquote
 
 from requests.utils import get_netrc_auth
 
@@ -291,6 +291,9 @@ def _process_auth(self):
                 # Handle http://username:password@hostname/
                 username = url.username
                 password = url.password or ''
+                # Decode percent-encoded characters in username and password
+                username = unquote(username)
+                password = unquote(password)
                 self.args.auth = AuthCredentials(
                     key=username,
                     value=password,
@@ -306,7 +309,7 @@ def _process_auth(self):
             if (not self.args.ignore_netrc
                     and self.args.auth is None
                     and plugin.netrc_parse):
-                # Only host needed, so it’s OK URL not finalized.
+                # Only host needed, so it's OK URL not finalized.
                 netrc_credentials = get_netrc_auth(self.args.url)
                 if netrc_credentials:
                     self.args.auth = AuthCredentials(
@@ -377,7 +380,7 @@ def _apply_no_options(self, no_options):
                 invalid.append(option)
 
         if invalid:
-            self.error(f'unrecognized arguments: {" ".join(invalid)}')
+            self.error(f'unrecognized arguments: {"".join(invalid)}')
 
     def _body_from_file(self, fd):
         """Read the data from a file-like object.
@@ -610,4 +613,4 @@ def error(self, message):
                 '''.rstrip()
             )
         )
-        self.exit(2)
+        self.exit(2)
\ No newline at end of file