What causes "Unable to login: %s" in ytdl-org/youtube-dl?

Verify the username/password pair logs in successfully in a normal browser session.

ytdl-org/youtube-dl · error · ExtractorError

Unable to login: %s

Error message

Unable to login: %s

What it means

PornHubBaseIE._login raises ExtractorError('Unable to login: %s' % message, expected=True) when the AJAX POST to the login endpoint returns JSON with success != '1' but includes a 'message' field. The interpolated text is the site's own failure reason (e.g. wrong username/password or CAPTCHA required). Expected=True makes it a reportable credential problem rather than an extractor crash.

Source

Thrown at youtube_dl/extractor/pornhub.py:115

        })

        response = self._download_json(
            'https://www.%s/front/authenticate' % host, None,
            'Logging in to %s' % site,
            data=urlencode_postdata(login_form),
            headers={
                'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
                'Referer': login_url,
                'X-Requested-With': 'XMLHttpRequest',
            })

        if response.get('success') == '1':
            self._logged_in = True
            return

        message = response.get('message')
        if message is not None:
            raise ExtractorError(
                'Unable to login: %s' % message, expected=True)

        raise ExtractorError('Unable to log in')


class PornHubIE(PornHubBaseIE):
    IE_DESC = 'PornHub and Thumbzilla'
    _VALID_URL = r'''(?x)
                    https?://
                        (?:
                            (?:[^/]+\.)?
                            %s
                            /(?:(?:view_video\.php|video/show)\?viewkey=|embed/)|
                            (?:www\.)?thumbzilla\.com/video/
                        )
                        (?P<id>[\da-z]+)
                    ''' % PornHubBaseIE._PORNHUB_HOST_RE
    _TESTS = [{

View on GitHub (pinned to 956b8c5855)

Solutions

Verify the username/password pair logs in successfully in a normal browser session.
If the message indicates a CAPTCHA, log in manually once in a browser and pass cookies (--cookies from a cookies.txt) instead of username/password.
Check the exact site message in the error text — it names the real failure (bad credentials, locked account, etc.).
Update youtube-dl, as login endpoint/parameter changes are fixed in newer releases.

Example fix

# before
youtube_dl --username me --password 'typo' URL

# after
# export browser cookies and skip password login
youtube_dl --cookies cookies.txt URL

Defensive patterns

Strategy: try-catch

Try / catch

try:
    ydl.extract_info(url)
except ExtractorError as e:
    if str(e).startswith('Unable to login:'):
        # fall back to cookie-based auth
        ...

Prevention

Prefer --cookies from a real browser session over username/password for this site.
Never hard-code credentials; read them from a secret store and verify in a browser first.
Watch the message text — it names the actual cause (bad password vs CAPTCHA).

When it happens

Trigger: Running with --username/--password where the credentials are wrong or the account requires a CAPTCHA; the POST to login_url with X-Requested-With/Referer headers returns {'success': '0', 'message': '...'}; partial two-factor or locked accounts also return here.

Common situations: Typo'd or expired passwords; PornHub intermittently requiring reCAPTCHA on API logins (which the extractor cannot solve); account locked/flagged; password managers inserting stale credentials; too many login attempts triggering anti-bot.

Related errors

AI-assisted analysis of ytdl-org/youtube-dl@956b8c5855 (2026-08-14). Data as JSON: /api/errors/88bb3b14ef89bbf2. Report an issue: GitHub.