diff --git a/archivebox/config.py b/archivebox/config.py
index 2ecc3415..6175a165 100644
--- a/archivebox/config.py
+++ b/archivebox/config.py
@@ -108,16 +108,17 @@ CONFIG_SCHEMA: Dict[str, ConfigDefaultDict] = {
         'CHECK_SSL_VALIDITY':       {'type': bool,  'default': True},
         'MEDIA_MAX_SIZE':           {'type': str,   'default': '750m'},
 
-        'CURL_USER_AGENT':          {'type': str,   'default': 'ArchiveBox/{VERSION} (+https://github.com/ArchiveBox/ArchiveBox/) curl/{CURL_VERSION}'},
-        'WGET_USER_AGENT':          {'type': str,   'default': 'ArchiveBox/{VERSION} (+https://github.com/ArchiveBox/ArchiveBox/) wget/{WGET_VERSION}'},
-        'CHROME_USER_AGENT':        {'type': str,   'default': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.75 Safari/537.36'},
+        'CURL_USER_AGENT':          {'type': str,   'default': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.61 Safari/537.36 ArchiveBox/{VERSION} (+https://github.com/ArchiveBox/ArchiveBox/) curl/{CURL_VERSION}'},
+        'WGET_USER_AGENT':          {'type': str,   'default': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.61 Safari/537.36 ArchiveBox/{VERSION} (+https://github.com/ArchiveBox/ArchiveBox/) wget/{WGET_VERSION}'},
+        'CHROME_USER_AGENT':        {'type': str,   'default': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.61 Safari/537.36 ArchiveBox/{VERSION} (+https://github.com/ArchiveBox/ArchiveBox/)'},
 
         'COOKIES_FILE':             {'type': str,   'default': None},
         'CHROME_USER_DATA_DIR':     {'type': str,   'default': None},
 
         'CHROME_HEADLESS':          {'type': bool,  'default': True},
         'CHROME_SANDBOX':           {'type': bool,  'default': lambda c: not c['IN_DOCKER']},
-        'YOUTUBEDL_ARGS':           {'type': list,  'default': lambda c: ['--write-description',
+        'YOUTUBEDL_ARGS':           {'type': list,  'default': lambda c: [
+                                                                '--write-description',
                                                                 '--write-info-json',
                                                                 '--write-annotations',
                                                                 '--write-thumbnail',