Yes — clearly sinful. Matthew 5:28 (lustful looking = adultery), Job 31:1 (covenant with eyes), consistent biblical call to flee sexual immorality. 2/100 Avoid.
Matthew 5:28: "But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart." Pornography is specifically designed to produce sexual arousal toward people other than your spouse. It is industrialized adultery-of-the-heart at scale. Job 31:1: "I made a covenant with my eyes not to look lustfully at a young woman." This ancient commitment reflects the biblical pattern of guarding the eyes as a spiritual discipline.
The biblical case against pornography is reinforced by documented psychological and relational harms. Pornography addiction activates the same neurological pathways as drug addiction, producing tolerance and withdrawal. Research consistently links pornography use to unrealistic sexual expectations, reduced marital satisfaction, and increased acceptance of sexual violence. It fuels human trafficking — most pornographic content involves genuine exploitation of vulnerable people regardless of whether performers appear to consent.
Pornography addiction is one of the most common struggles among Christian men and an increasing concern for women. Shame and secrecy sustain addiction; confession, accountability, and grace break it. Every Man's Battle (Steve Arterburn) and Covenant Eyes (accountability software) are practical resources. The biblical call is clear — but so is the grace available for those in the struggle. See also Is Gambling a Sin? for the addiction-and-Scripture framework.
For practical help with accountability: Covenant Eyes accountability software.
For the specific question of OnlyFans — which adds parasocial intimacy elements to traditional pornography concerns — see our guide Is OnlyFans a Sin?