The news came four years after the breach took place in 2012, which LinkedIn said at the time only 6.4 million accounts were affected.
Hunt said Tuesday in a blog post that he had loaded the 164 million records into Have I Been Pwned, which lets users search their associated email addresses to see if their records show up.
According to a tweet, 16 percent of accounts in the hacked data dump were already in the Have I Been Pwned database.
LinkedIn is currently rolling out a password reset to affected users. A LinkedIn spokesperson said the company has finished invalidating all passwords it believes were most at risk, and has sent emails out to members. But those who weren't affected by the breach won't receive a password reset note, the spokesperson said.
For now, it's better to be proactive and change your password, with or without an emailed reminder.