Cardboard

Cardboard is an AI-native video editing company that graduated from Y Combinator's Winter 2026 batch. The company was founded to eliminate the manual, time-intensive process of editing video content for growth and marketing teams. Its core technology applies multimodal large language models to understand raw video footage in the context of a team's goals, then autonomously generates a polished first cut — compressing what previously took hours into minutes.\n\nCardboard's platform runs entirely in the browser using WebGPU, removing the need for desktop software installation and enabling collaboration across teams without version conflicts. The agentic editor accepts footage alongside a creative brief or campaign goal, then makes sequencing, pacing, and cut decisions in line with that intent. This goal-aware editing approach is designed for performance marketing teams, social media managers, and growth hackers who produce high volumes of short-form content across platforms like TikTok, Instagram, and YouTube Shorts.\n\nAs a YC W26 company, Cardboard is in early-stage growth and is focused on building its customer base among digital marketing teams and agencies. The product addresses a significant bottleneck in content pipelines where video editing talent and turnaround time limit the volume and velocity of campaigns. By democratizing professional-quality editing through agentic AI, Cardboard positions itself to become essential infrastructure for high-output growth teams that treat video as a core performance channel.