XKCD
HIGH RISKData breach — July 2019
In July 2019, the forum for webcomic XKCD suffered a data breach that impacted 562k subscribers. The breached phpBB forum leaked usernames, email and IP addresses and passwords stored in MD5 phpBB3 format. The data was provided to HIBP by white hat security researcher and data analyst Adam Davies.
search Check if you were affected — freeData exposed in this breach
What happened in the XKCD data breach?
In July 2019, the forum for webcomic XKCD suffered a data breach that impacted 562k subscribers. The breached phpBB forum leaked usernames, email and IP addresses and passwords stored in MD5 phpBB3 format. The data was provided to HIBP by white hat security researcher and data analyst Adam Davies.
The exposed data included 4 types of personal information. Because passwords were exposed, users who reused their password on other sites are at particular risk. Learn more about what a data breach means for you.
Quick answer — was XKCD hacked?
Yes. XKCD was breached in July 2019. The breach exposed 561,991 records including email addresses, ip addresses, passwords. This breach has been independently verified. If your email was involved, your data may still be at risk today. Check if you were affected.
Why was the XKCD breach so dangerous?
The XKCD breach exposed 561,991 records — that is a large number of compromised accounts. The combination of email addresses, ip addresses, passwords makes this a high-risk breach that requires immediate action.
Because passwords were exposed, attackers can use credential stuffing to automatically test your XKCD password against hundreds of other websites. If you reused your password anywhere, those accounts are now at risk. Read more about what happens to your data after a breach.
Don't wait to find out — check if your email was exposed in this breach now.
What data was stolen in the XKCD breach?
Email addresses — used for phishing attacks and credential stuffing against your other accounts
IP addresses — combined with other data, used for identity theft and physical fraud
Passwords — can be used to access your accounts directly or cracked to reveal your actual password
Usernames — used to build profiles and target you with personalised scams
Is the XKCD breach still dangerous in 2026?
Yes. Stolen data from the XKCD breach remains dangerous years after the incident. Research shows that over 65% of stolen credentials from older breaches have never been changed by the account holders. Attackers routinely compile data from multiple breaches to build complete profiles, and credentials from 2019 are still actively used in credential stuffing attacks today.
Personal information like email addresses, phone numbers, and dates of birth never expire. Even if you changed your XKCD password, the other exposed data can be combined with information from other breaches to target you. Learn more about how long stolen data stays dangerous.
Frequently asked about the XKCD breach
Approximately 561,991 user records were exposed in the XKCD breach in July 2019.
Yes. Leaked credentials are actively used in credential stuffing attacks years after a breach. If you reused your XKCD password elsewhere and haven't changed it, those accounts remain at risk today.
Enter your email in the free checker on EmailLeaked. We scan 12 billion+ breach records including the full XKCD dataset and tell you instantly whether your email was exposed and what data was taken.
Change your XKCD password immediately, change any other account where you used the same password, enable two-factor authentication on all important accounts, and monitor for phishing emails over the next 90 days.
Who was affected by the XKCD breach?
The XKCD data breach affected approximately 561,991 users who had accounts with the service. While not the largest breach on record, it still represents a significant number of compromised accounts in our database of 970+ known breaches.
If you ever created an account with XKCD or used their services, your data may have been included in this breach. Check your email now to find out. You can also read our guide on what to do immediately after a data breach.
If your email was in the XKCD breach
Change your XKCD password immediately
Go to XKCD and change your password right now. Use a strong, unique password that you have never used anywhere else.
Change any account sharing that password
If you used the same password on other sites, change it on every one of them. Attackers test stolen credentials on hundreds of popular sites within hours.
Enable two-factor authentication
Turn on 2FA on XKCD and every important account. Even if your password is known, attackers cannot get in without the second factor.
Check your other accounts for this breach
Run a full email check to see every breach your email appears in — not just this one.
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