Y Combinator W25 Demo Day: Startups Building the Future of AI
One of Silicon Valley’s most well-known startup accelerators, Y Combinator, held its Winter 2025 Demo Day on Wednesday, presenting the latest ventures from its newest cohort of 160 startups. YC has a successful track record, with alumni including Stripe, Airbnb, and Reddit. This year’s focus is clearly on AI, with many startups developing tools to enhance and support AI agents.
Rather than creating their own AI agents, many of these companies are concentrating on building support tools, which stood out amidst the multitude of AI agent-focused ventures. While several other promising companies also presented, the following startups particularly caught our attention:
Abundant
What it does: API for agent teleoperation
Why it’s a fave: Inspired by Waymo’s success with autonomous robotaxis, Abundant offers a platform allowing human operators to remotely take control of AI agents when issues arise. The API is designed to detect agent failures, allowing for seamless human intervention.
Browser Use
What it does: Enables AI agents to navigate web browsers
Why it’s a fave: Browser Use gained rapid attention earlier this week when a Chinese AI agent, Manus, used its open-source tool to click through website menus and complete forms. Daily downloads jumped to 28,000, according to one of the founders. As web-browsing AI agents like OpenAI’s Operator gain traction, Browser Use provides a compelling open-source solution.
GradeWiz
What it does: Automates grading tasks using AI
Why it’s a fave: Recognizing the time drain of grading for Teaching Assistants (TAs), GradeWiz automates the process, freeing up TAs to focus on direct student instruction. Founded by Cornell TAs who sought to alleviate this tedious task, the platform leverages AI to streamline the workload.
Misprint
What it does: A platform for buying and selling Pokémon cards
What it’s a fave: Misprint has a compelling origin story: co-founder Eva Herget left Goldman Sachs to focus on selling Pokémon cards full-time. Now, Herget and her co-founder built a platform for trading cards and other collectibles using a bid/ask style setup that mimics the stock market. The secondhand Pokémon card market is substantial, with $3.5 billion in sales annually, according to Misprint.
Nextbyte
What it does: Uses AI to help companies find the best “vibe coders”
Why it’s a fave: As AI-assisted coding becomes more prevalent, Nextbyte seeks to help companies find the developers best suited to leverage this technology. Their AI model powers interview questions that assess coders’ ability to effectively use AI in their work.
Pickle
What it does: AI clone for Zoom calls
Why it’s a fave: Pickle provides a solution for those who want to present a polished appearance in virtual meetings. It allows users to create a virtual “clone” of themselves, complete with lip-syncing, projecting a more composed version on screen. Targeting remote teams, the company reports over 1,500 paying users.
Rebolt
What it does: AI agents to automate restaurant management
Why it’s a fave: Rebolt aims to automate restaurant management tasks, such as inventory management, which are often handled manually. The use of AI agents automates some of this work and, according to the company, they’re in pricing talks with the parent company of Burger King.
Red Barn Robotics
What it does: A Roomba for weeds on a farm. It’s a robot that removes weeds autonomously.
Why it’s a fave: Red Barn Robotics addresses the labor-intensive task of removing weeds, which can significantly impact farm yields. The company’s “Field Hand” robot is designed to be faster and more cost-effective than manual labor. The company has signed $5 million in LOIs for the upcoming growing season.
Retrofit
What it does: An AI-curated vintage clothing marketplace
Why it’s a fave: Retrofit uses AI to sift through thousands of vintage listings, creating a marketplace tailored to current trends. The platform simplifies the process of shopping for vintage clothes online through the use of AI. The website also has an appealing design.
Splash
What it does: Autonomous patrol boats to patrol sea borders
Why it’s a fave: Splash builds small patrol boats that autonomously patrol sea borders and offers autonomy in defense technology. The startup has already completed 200 miles of autonomous cruising in the San Francisco Bay Area and claims an impressive 800-mile range.
