Lemon Slice was co-founded by Lina Colucci, Sidney Primas, and Andrew Weitz, a team of PhDs with backgrounds in AI and visual storytelling from MIT, Harvard, Stanford, and Duke. The company set out to add a real-time video layer to AI chatbots and assistants.
Its flagship Lemon Slice-2 model can transform a single image into a live, conversational avatar, generating video in real time rather than relying on pre-rendered clips. The 20-billion-parameter diffusion-based model streams at roughly 20 frames per second on a single GPU, enabling interactive, two-way video experiences.
Lemon Slice launched publicly in December 2025 with a $10.5M seed round from Matrix Partners and Y Combinator, with angels including Dropbox CTO Arash Ferdowsi, Twitch co-founder Emmett Shear, and The Chainsmokers. The model is available through an API and an embeddable widget that companies can drop into sites with a single line of code.
Target use cases span education, language learning, e-commerce, and corporate training. The company says it has guardrails, including LLM-based content moderation, to prevent unauthorized face or voice cloning.