Lemon Slice
Category: Generative Media (Image / Video)
A generative AI platform building real-time, interactive video foundation models that enable developers to create expressive, talking AI avatars for web and mobile applications. Lemon Slice was founded in 2024. The company is led by Lina Colucci. Based in San Francisco, United States. Team size: 3-10. Total funding raised: $16.0M. Latest round: Seed Round ($10.5M, Dec 2025). Key investors include Matrix Partners, Y Combinator, Mantis Venture Capital, The Chainsmokers, Emmett Shear, Arash Ferdowsi.
- Founded
- 2024
- Headquarters
- San Francisco, United States
- Team size
- 3-10
- Total funding
- $16.0M
Value proposition
Delivers hyper-realistic AI avatars with sub-second latency (real-time interaction), solving the 'uncanny valley' problem through proprietary models that handle emotional expressiveness and non-verbal cues better than existing solutions.
Products and solutions
Lemon Slice-2 real-time interactive avatar API, Embeddable website video chat widget, Zero-shot custom character generation (single image), LemonSlice Actions (programmable avatar motions), LiveKit Agents integration
Unique value
Leverages a proprietary 'synthetic data' pipeline (derived from the team's previous startup, Infinity AI) to train video models on massive datasets of perfectly labeled human motion and expression, bypassing the limits of real-world data collection.
Target customer
Developers, Enterprise (Customer Support, Sales), EdTech platforms, and Digital Creators
Industries served
Generative AI / Synthetic Media, Customer Experience (CX) & Support, Digital Entertainment & Gaming, Education Technology (EdTech)
Technology advantage
Lemon Slice-2 is a ~20B-parameter video diffusion transformer streaming interactive avatars at 20fps on a single GPU from one photo; generates every pixel end-to-end for expressive face/body motion and interruptible two-way conversation.
How they differentiate
Real-time interactive video (Lemon Slice-2 ~20fps on a single GPU) optimized for interruptible, two-way conversation from a single image—vs. static/linear avatar video tools.
Main competitors
HeyGen, Synthesia, Tavus, D-ID
Key partnerships
Microsoft, LiveKit, Daily, ElevenLabs, Deepgram, Theodore Roosevelt Presidential Library, Y Combinator, Matrix Partners
Notable customers
Microsoft (Theodore Roosevelt Presidential Library exhibit), Daily, ElevenLabs
Major milestones
Raised $5M Seed as Infinity AI in Dec 2022, Graduated Y Combinator W24 Batch in Apr 2024, Rebranded to Lemon Slice and launched real-time avatar product in 2025, Raised $10.5M Seed (Matrix, YC et al.) and launched Lemon Slice-2 (Dec 2025), LiveKit integration (Feb 2026), LemonSlice Actions product launch (May 2026), Microsoft + Theodore Roosevelt Presidential Library live avatar exhibit (Jul 2026)
Growth metrics
Team of ~8 (Dec 2025, still cited ~8 mid-2026); Lemon Slice-2 streams interactive avatars at 20fps on a single GPU; YC W24 era: 110+ customers / 20% WoW (historical).
Market positioning
Real-time interactive video infrastructure for developers (API/SDK focus)
Geographic focus
North America, Global
Patents and IP
Proprietary 'Video Foundation Models' and synthetic data generation pipelines
About Lina Colucci
Co-founder of Infinity AI (synthetic data) and Edge Analytics (data science consulting). PhD in Medical Engineering and Medical Physics from Harvard-MIT Health Sciences and Technology. Expert in machine learning and generative video.
Latest news about Lemon Slice
- San Francisco-based Lemon Slice secured $10.5M in Seed funding led by Matrix Partners and Y Combinator to scale its interactive video platform. Its proprietary 20B parameter model generates real-time,
- Lemon Slice launched with 10.5 million dollars in seed funding to scale real-time interactive AI avatars. The company unveiled Lemon Slice-2, a 20-billion-parameter video diffusion model capable of ge
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Official website: https://lemonslice.com
