YT: TVHTML5 API JSON: ERROR: Sign in to confirm youre not a bot

[tansy]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2025.01.16
• 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

Description and Verbose log

YT: TVHTML5 API JSON: ERROR: Sign in to confirm youre not a bot

Using newest nightly build (25-01-16), downloading format list or video itself fails with this error:
ERROR: Sign in to confirm youre not a bot
while using earlier version (25-01-06) does not.

$ ./ytdl-2025.01.06 -F https://www.youtube.com/watch?v=OjOiWe9MHNk
[youtube] OjOiWe9MHNk: Downloading webpage
[youtube] OjOiWe9MHNk: Downloading API JSON
[info] Available formats for OjOiWe9MHNk:
format code  extension  resolution note
599          m4a        audio only audio_quality_ultralow   30k , m4a_dash container, mp4a.40.5 (22050Hz), 6.87MiB
599-drc      m4a        audio only audio_quality_ultralow   30k , m4a_dash container, mp4a.40.5 (22050Hz), 6.87MiB
(...)
313          webm       3840x2160  2160p 11113k , webm_dash container, vp9, 30fps, video only, 2.42GiB
18           mp4        640x360    360p  459k , avc1.42001E, 30fps, mp4a.40.2 (44100Hz), 102.64MiB (best)

$ ./ytdl-2025.01.16 -F https://www.youtube.com/watch?v=OjOiWe9MHNk
[youtube] OjOiWe9MHNk: Downloading webpage
[youtube] OjOiWe9MHNk: Downloading TVHTML5 API JSON
ERROR: Sign in to confirm you’re not a bot
This helps protect our community. Learn more

Verbose

$ ./youtube-dl-1 -v -F https://www.youtube.com/watch?v=OjOiWe9MHNk
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'-F', u'https://www.youtube.com/watch?v=OjOiWe9MHNk']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2025.01.16 [55ad8a24c] (single file build)
[debug] ** This version was built from the latest master code at https://github.com/ytdl-org/youtube-dl.
[debug] ** For support, visit the main site.
[debug] Python 2.7.11 (CPython i686 32bit) - OpenSSL 1.0.1e 11 Feb 2013 - glibc 2.0
[debug] exe versions: none
[debug] Proxy map: {}
[youtube] OjOiWe9MHNk: Downloading webpage
[youtube] OjOiWe9MHNk: Downloading TVHTML5 API JSON
ERROR: Sign in to confirm you’re not a bot
This helps protect our community. Learn more
Traceback (most recent call last):
  File "./ytdl-nightly-2025.01.16/youtube_dl/YoutubeDL.py", line 879, in wrapper
    return func(self, *args, **kwargs)
  File "./ytdl-nightly-2025.01.16/youtube_dl/YoutubeDL.py", line 975, in __extract_info
    ie_result = ie.extract(url)
  File "./ytdl-nightly-2025.01.16/youtube_dl/extractor/common.py", line 571, in extract
    ie_result = self._real_extract(url)
  File "./ytdl-nightly-2025.01.16/youtube_dl/extractor/youtube.py", line 2387, in _real_extract
    raise ExtractorError(reason, expected=True)
ExtractorError: Sign in to confirm you\u2019re not a bot
This helps protect our community. Learn more

Same for download.

1c1
< $ ./ytdl-2025.01.16 -v -F https://www.youtube.com/watch?v=OjOiWe9MHNk
---
> $ ./ytdl-2025.01.16 -v -f 18 https://www.youtube.com/watch?v=OjOiWe9MHNk
5c5
< [debug] Command-line args: [u'-v', u'-F', u'https://www.youtube.com/watch?v=OjOiWe9MHNk']
---
> [debug] Command-line args: [u'-v', u'-f', u'18', u'https://www.youtube.com/watch?v=OjOiWe9MHNk']

It seems to be triggered/aggrevated by adding 'level/s of indirection', I mean 'links' to it, but I'm not entirely sure how could it cause it.

$ echo /path/to/ytdl-nightly-2025.01.06 \"\$\@\" > ytdl-2025.01.06; chmod +x ytdl-2025.01.06
$ echo /path/to/ytdl-nightly-2025.01.16 \"\$\@\" > ytdl-2025.01.16; chmod +x ytdl-2025.01.16

Worse part of it is that it sometimes work. And when it works then few times in a row, when doesn't the same - time and time again.

[dirkf]

You can have 2025.01.16 and have some chance of getting a successful download other than format 18, or 2025.01.06 and have no such chance.

Also, #32960, though I agree that it seems to be more prevalent with the tv client.

Possibly sign-in will be permanently forced on the tv client as it is with some others, and as JS has now been forced on G search. "Don't be evil", indeed.

[tansy]

So I tested it and success ratio is like 1:2.

$ while : ; do ytdl-nightly-2025.01.16 -v -f 18 https://www.youtube.com/watch?v=S2FlRxQJQyw; echo $? >> exit-status; rm -f *.mp4; printf "\n####\n\n"; done
$ cat exit-status
 1 1 0 0 1 1 0 0 1 0 1 1 1 0 0 0 1 0 1 0 0 1 1 1 1 0 1 0 1 0 0 1 0 1 0 1 0 1 1 1 1 0 1 0 0 1 0 1 0 1

When I add famous user agent, I get different error (most of the time):

$ UA="Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.6533.103 Mobile Safari/537.36"
$ ./ytdl-nightly-2025.01.16 -v --user-agent "$UA" -f 18 https://www.youtube.com/watch?v=S2FlRxQJQyw; echo $? >> exit-status; rm -f *.mp4; printf "\n####\n\n"; done

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'--user-agent', u'Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.6533.103 Mobile Safari/537.36', u'-f', u'18', u'https://www.youtube.com/watch?v=S2FlRxQJQyw']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2025.01.16 [55ad8a24c] (single file build)
[debug] ** This version was built from the latest master code at https://github.com/ytdl-org/youtube-dl.
[debug] ** For support, visit the main site.
[debug] Python 2.7.11 (CPython i686 32bit) - OpenSSL 1.0.1e 11 Feb 2013 - glibc 2.0
[debug] exe versions: none
[debug] Proxy map: {}
[youtube] S2FlRxQJQyw: Downloading webpage
[youtube] S2FlRxQJQyw: Downloading TVHTML5 API JSON
[debug] [youtube] Decrypted nsig SkeAZi4_-LXAJBP5Q => nlNxdduN3HzMIg
[debug] [youtube] Decrypted nsig 5IBsrSGHpC1JcsvRu => bjJrNuC7KWdwoQ
[youtube] S2FlRxQJQyw: Downloading API JSON
ERROR: Missing "title" field in extractor result; please report this issue on https://github.com/ytdl-org/youtube-dl/issues , using the appropriate issue template. Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose option and include the complete output.
Traceback (most recent call last):
  File "./ytdl-nightly-2025.01.16/youtube_dl/YoutubeDL.py", line 879, in wrapper
    return func(self, *args, **kwargs)
  File "./ytdl-nightly-2025.01.16/youtube_dl/YoutubeDL.py", line 986, in __extract_info
    return self.process_ie_result(ie_result, download, extra_info)
  File "./ytdl-nightly-2025.01.16/youtube_dl/YoutubeDL.py", line 1020, in process_ie_result
    return self.process_video_result(ie_result, download=download)
  File "./ytdl-nightly-2025.01.16/youtube_dl/YoutubeDL.py", line 1648, in process_video_result
    raise ExtractorError('Missing "title" field in extractor result')
ExtractorError: Missing "title" field in extractor result; please report this issue on https://github.com/ytdl-org/youtube-dl/issues , using the appropriate issue template. Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose option and include the complete output.

$ UA="Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.6533.103 Mobile Safari/537.36"
$ while : ; do ytdl-nightly-2025.01.16 -v --user-agent "$UA" -f 18 https://www.youtube.com/watch?v=S2FlRxQJQyw; echo $? >> exit-status; rm -f *.mp4; printf "\n####\n\n"; done
$ cat exit-status
 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

and success ratio drops to 0.