ytdl-org/youtube-dl · error · ExtractorError

Cannot identify player %r

Error message

Cannot identify player %r

What it means

Raised by YoutubeIE._extract_player_info when the player URL does not match _PLAYER_INFO_RE, so the player version/id cannot be parsed. The original regex failure is chained as cause. This almost always means YouTube changed its player URL format (the code builds URLs like https://www.youtube.com/s/player/<version>/player_ias.vflset/en_US/base.js).

Source

Thrown at youtube_dl/extractor/youtube.py:1774

    def _download_player_url(self, video_id, fatal=False):
        res = self._download_webpage(
            'https://www.youtube.com/iframe_api',
            note='Downloading iframe API JS', video_id=video_id, fatal=fatal)
        player_version = self._search_regex(
            r'player\\?/([0-9a-fA-F]{8})\\?/', res or '', 'player version', fatal=fatal,
            default=NO_DEFAULT if res else None) or None
        return player_version and 'https://www.youtube.com/s/player/{0}/player_ias.vflset/en_US/base.js'.format(player_version)

    def _signature_cache_id(self, example_sig):
        """ Return a string representation of a signature """
        return '.'.join(compat_str(len(part)) for part in example_sig.split('.'))

    def _extract_player_info(self, player_url):
        try:
            return self._search_regex(
                self._PLAYER_INFO_RE, player_url, 'player info', group='id')
        except ExtractorError as e:
            raise ExtractorError(
                'Cannot identify player %r' % (player_url,), cause=e)

    def _player_js_cache_key(self, player_url, extra_id=None, _cache={}):
        if player_url not in _cache:
            player_id = self._extract_player_info(player_url)
            player_path = remove_start(
                compat_urllib_parse.urlparse(player_url).path,
                '/s/player/{0}/'.format(player_id))
            variant = next((k for k, v in self._PLAYER_JS_VARIANT_MAP
                           if v == player_path), None)
            if not variant:
                variant = next(
                    (k for k, v in self._PLAYER_JS_VARIANT_MAP
                     if re.match(re.escape(v).replace('en_US', r'\w+') + '$', player_path)),
                    None)
            if not variant:
                self.write_debug(
                    'Unable to determine player JS variant\n'

View on GitHub (pinned to 956b8c5855)

Solutions

  1. Update youtube-dl to the latest release (or yt-dlp, which tracks player URL changes much faster) — regex fixes ship as patches.
  2. Print player_url (the message includes it via %r) and compare with the current base.js URL in a browser; adjust _PLAYER_INFO_RE if you maintain a fork.
  3. Clear cached player data so stale player URLs are not reused (the signature cache keys off player_url).
  4. If embedding the library, pin to a known-good version and schedule prompt updates, since YouTube-side changes break old regexes.
Defensive patterns

Strategy: try-catch

Validate before calling

import re
PLAYER_INFO_RE = YoutubeIE._PLAYER_INFO_RE

def player_url_parseable(player_url: str) -> bool:
    return player_url is not None and re.search(PLAYER_INFO_RE, player_url) is not None

Try / catch

try:
    ...extraction...
except ExtractorError as e:
    if 'Cannot identify player' in str(e):
        update_youtube_dl()  # player URL format changed; update first
    raise

Prevention

When it happens

Trigger: Any code path that calls _extract_player_info (signature deciphering, nsig decryption, STS extraction) with a player_url whose shape no longer matches _PLAYER_INFO_RE — e.g. new URL schemes, a different path layout, or a None/relative URL that slipped through.

Common situations: YouTube rolls out a new player URL pattern; youtube-dl version is old relative to YouTube changes; the player URL came from a cached page or an embedded player host with a different path.

Related errors

AI-assisted analysis of ytdl-org/youtube-dl@956b8c5855 (2026-08-14). Data as JSON: /api/errors/8fa617a3a48bf4ec. Report an issue: GitHub.