Largest Recorded DDoS Attack is 3.8 Tbps
CLoudflare just blocked the current record DDoS attack: https://blog.cloudflare.com/how-cloudflare-auto-mitigated-world-record-3-8-tbps-ddos-attack/
. (Lots of good information on the attack, and DDoS in general, at the link.)
News https://www.bleepingcomputer.com/news/security/cloudflare-blocks-largest-recorded-ddos-attack-peaking-at-38tbps/
.
https://www.schneier.com/blog/archives/2024/10/largest-recorded-ddos-attack-is-3-8-tbps.html