YouTube Download: Unable to extract Initial JS player signature function name #17347

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opened 2026-02-21 09:27:21 -05:00 by deekerman · 0 comments

deekerman commented

2026-02-21 09:27:21 -05:00

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Originally created by @albertaparicio on GitHub (Jul 11, 2019).

Checklist

I'm reporting a broken site support issue
I've verified that I'm running youtube-dl version 2019.07.02
I've checked that all provided URLs are alive and playable in a browser
I've checked that all URLs and arguments with special characters are properly quoted or escaped
I've searched the bugtracker for similar bug reports including closed ones
I've read bugs section in FAQ

Verbose log

$ youtube-dl https://www.youtube.com/watch\?v\=wLoYIBEZEfw -v
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['https://www.youtube.com/watch?v=wLoYIBEZEfw', '-v']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.05.20
[debug] Python version 3.7.3 (CPython) - Linux-5.1.16-200.fc29.x86_64-x86_64-with-fedora-29-Twenty_Nine
[debug] exe versions: ffmpeg 4.0.4, ffprobe 4.0.4
[debug] Proxy map: {}
[youtube] wLoYIBEZEfw: Downloading webpage
[youtube] wLoYIBEZEfw: Downloading video info webpage
[youtube] {18} signature length 107, html5 player vfladvVLE
[youtube] wLoYIBEZEfw: Downloading player https://www.youtube.com/yts/jsbin/player_ias-vfladvVLE/en_US/base.js
ERROR: Signature extraction failed: Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
 (caused by RegexNotFoundError('Unable to extract \x1b[0;34mInitial JS player signature function name\x1b[0m; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.')); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/YoutubeDL.py", line 796, in extract_info
    ie_result = ie.extract(url)
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 529, in extract
    ie_result = self._real_extract(url)
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1989, in _real_extract
    encrypted_sig, video_id, player_url, age_gate)
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1352, in _decrypt_signature
    'Signature extraction failed: ' + tb, cause=e)
youtube_dl.utils.ExtractorError: Signature extraction failed: Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
 (caused by RegexNotFoundError('Unable to extract \x1b[0;34mInitial JS player signature function name\x1b[0m; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.')); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

Description

When trying to download a video from YouTube I get this error. I have found it in the past and dissappeared with an update, but it seems it is back

Originally created by @albertaparicio on GitHub (Jul 11, 2019).  ## Checklist  - [ ] I'm reporting a broken site support issue - [x] I've verified that I'm running youtube-dl version **2019.07.02** - [x] I've checked that all provided URLs are alive and playable in a browser - [x] I've checked that all URLs and arguments with special characters are properly quoted or escaped - [x] I've searched the bugtracker for similar bug reports including closed ones - [x] I've read bugs section in FAQ ## Verbose log  ``` $ youtube-dl https://www.youtube.com/watch\?v\=wLoYIBEZEfw -v [debug] System config: [] [debug] User config: [] [debug] Custom config: [] [debug] Command-line args: ['https://www.youtube.com/watch?v=wLoYIBEZEfw', '-v'] [debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8 [debug] youtube-dl version 2019.05.20 [debug] Python version 3.7.3 (CPython) - Linux-5.1.16-200.fc29.x86_64-x86_64-with-fedora-29-Twenty_Nine [debug] exe versions: ffmpeg 4.0.4, ffprobe 4.0.4 [debug] Proxy map: {} [youtube] wLoYIBEZEfw: Downloading webpage [youtube] wLoYIBEZEfw: Downloading video info webpage [youtube] {18} signature length 107, html5 player vfladvVLE [youtube] wLoYIBEZEfw: Downloading player https://www.youtube.com/yts/jsbin/player_ias-vfladvVLE/en_US/base.js ERROR: Signature extraction failed: Traceback (most recent call last): File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature video_id, player_url, s File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function res = self._parse_sig_js(code) File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js jscode, 'Initial JS player signature function name', group='sig') File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex raise RegexNotFoundError('Unable to extract %s' % _name) youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output. (caused by RegexNotFoundError('Unable to extract \x1b[0;34mInitial JS player signature function name\x1b[0m; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.')); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output. Traceback (most recent call last): File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature video_id, player_url, s File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function res = self._parse_sig_js(code) File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js jscode, 'Initial JS player signature function name', group='sig') File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex raise RegexNotFoundError('Unable to extract %s' % _name) youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output. Traceback (most recent call last): File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature video_id, player_url, s File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function res = self._parse_sig_js(code) File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js jscode, 'Initial JS player signature function name', group='sig') File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex raise RegexNotFoundError('Unable to extract %s' % _name) youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output. During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/usr/local/lib/python3.7/site-packages/youtube_dl/YoutubeDL.py", line 796, in extract_info ie_result = ie.extract(url) File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 529, in extract ie_result = self._real_extract(url) File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1989, in _real_extract encrypted_sig, video_id, player_url, age_gate) File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1352, in _decrypt_signature 'Signature extraction failed: ' + tb, cause=e) youtube_dl.utils.ExtractorError: Signature extraction failed: Traceback (most recent call last): File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature video_id, player_url, s File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function res = self._parse_sig_js(code) File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js jscode, 'Initial JS player signature function name', group='sig') File "/usr/local/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex raise RegexNotFoundError('Unable to extract %s' % _name) youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output. (caused by RegexNotFoundError('Unable to extract \x1b[0;34mInitial JS player signature function name\x1b[0m; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.')); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output. ``` ## Description  When trying to download a video from YouTube I get this error. I have found it in the past and dissappeared with an update, but it seems it is back

deekerman added the

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2026-02-21 09:27:21 -05:00

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starred/youtube-dl-ytdl-org#17347

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