In an era where climate consciousness meets digital innovation, two of Gen Z’s most prominent young changemakers—Phoebe Gates and Sophia Kianni—have teamed up to launch a revolutionary fashion-tech startup: Phia. Positioned as the go-to secondhand shopping platform for Gen Z, Phia isn’t just an app—it’s a cultural movement aimed at transforming how young people buy, wear, and think about clothes.
With environmental sustainability at its core and digital fluency baked into its user experience, Phia is already being hailed as the Depop disruptor and a potential game-changer for the circular fashion economy. The duo’s mission is ambitious but clear: to make secondhand shopping more ethical, accessible, and, above all, cool.
Fashion Meets Mission: Why Phia Was Born
The idea for Phia was sparked during a climate tech conference in 2023, where Phoebe Gates—young philanthropist, fashion advocate, and daughter of Bill Gates—met Sophia Kianni, the Iranian-American climate activist and founder of Climate Cardinals. Both women bonded over a shared frustration: the glaring disconnect between Gen Z’s climate concerns and their fast-fashion habits.
Despite being the most eco-aware generation, Gen Z remains one of the highest consumers of fast fashion. Gates and Kianni wanted to tackle this paradox head-on. The solution? A stylish, AI-driven app that would make secondhand shopping as intuitive and engaging as scrolling TikTok.
Inside Phia: What Makes It Different?
At first glance, Phia looks like a hybrid of a fashion-forward resale platform and a digital social club. But peel back the sleek UI and what emerges is a robust, intelligent, and purpose-driven platform built specifically for how Gen Z discovers and shops.
Key Features:
- AI-Style Matching: Users upload their wardrobe or favorite looks, and Phia suggests secondhand items that match their vibe, color palette, or trending aesthetics.
- Climate Impact Score: Every purchase is tagged with the amount of water, carbon, and waste saved by opting for pre-loved clothing.
- Social Closet Sharing: A friend feature lets users browse, comment on, and even borrow or swap pieces virtually with people in their network.
- Drop Culture 2.0: Exclusive “Phia Drops” feature curated collections from student designers, fashion influencers, and vintage curators—reviving Y2K, Indie Sleaze, and Cottagecore with a sustainable twist.
Tech-Backed Sustainability
Phia isn’t just a marketplace—it’s a tech-powered sustainability engine. The app integrates with blockchain for authenticity tracking, uses machine learning to recommend styles based on user behavior and environmental impact, and employs reverse image search to help users find similar secondhand versions of their fast-fashion wishlist items.
Every garment listed on the platform is assigned a “Phia Footprint Score”, which factors in textile composition, lifecycle emissions, and geographic shipping distance. This nudges users toward greener choices without guilt-tripping—a balance Gates and Kianni consider essential for creating lasting behavior change.
The Team and Vision
Backed by a diverse team of engineers, fashion historians, environmental scientists, and Gen Z creators, Phia has quickly grown from a dorm-room dream to a venture-backed startup with serious momentum.
The founding team includes:
- Phoebe Gates: Bringing the fashion credibility, philanthropic vision, and tech-forward thinking cultivated at Stanford and through her Gates Foundation work.
- Sophia Kianni: Driving the climate strategy, community outreach, and ethical sourcing roadmap, building on her global network through UN climate summits and youth advocacy.
Together, they’ve assembled a board of advisors that includes sustainable fashion pioneer Stella McCartney, venture capitalist Aileen Lee, and environmental journalist Leah Thomas.
The company has raised $50 million in seed and Series A funding rounds from climate-tech investors, sustainable fashion incubators, and mission-driven funds focused on female-led startups.
Phia’s Cultural Moment
Since its beta launch in early 2025, Phia has amassed over 1.3 million users, with 75% of them aged between 16 and 24. It’s already trending on TikTok under hashtags like #PhiaFinds and #SecondhandChic. Celebrities from Zendaya to Olivia Rodrigo have been spotted sporting Phia-sourced pieces, sparking viral interest.
The platform’s success lies in its cultural fluency. Phia understands that Gen Z doesn’t just want to buy fashion—they want to participate in it. That’s why the app includes:
- Creator collabs: Digital thrift challenges, closet tours, and haul breakdowns featuring micro-influencers and college stylists.
- Gamified shopping: Users earn “Phia Points” for sustainable behavior, which can be used for discounts, early access drops, or donations to climate orgs.
- Mini-docs and education: Bite-sized content exploring topics like textile waste, colonialism in fashion, and upcycling tutorials, created by diverse youth voices.
A Future Beyond Fashion
What sets Phia apart is its vision beyond resale. Gates and Kianni see the app as the foundation for a broader ecosystem—what they call a “climate-conscious commerce platform”. Upcoming features include:
- Circular Repair Network: Matching users with local tailors and upcyclers to extend garment lifespans.
- Climate Credit Wallet: A loyalty program that tracks your sustainable shopping impact and lets you offset future emissions.
- Virtual Fashion IDs: Digital passports for clothing that track ownership history and care tips, encouraging repair and reuse.
The long-term roadmap includes expansion into other circular economy sectors—such as secondhand tech, home goods, and upcycled furniture. For now, fashion is the beachhead. But for Gates and Kianni, Phia is just the beginning.
The Skepticism—and the Response
Naturally, critics have surfaced. Some argue that Phia still feeds into the overconsumption mindset, albeit in a greener wrapper. Others question whether a VC-funded platform can truly prioritize ethics over scale.
But Gates and Kianni aren’t dodging the criticism—they’re actively engaging with it. In their quarterly “Transparency Town Halls,” they openly discuss revenue models, user feedback, and decisions about content moderation, seller approval, and equity.
They’ve also pledged that at least 10% of company profits will be reinvested into environmental education for marginalized youth and grants for BIPOC circular fashion entrepreneurs.
Conclusion: Style, Substance, and a Generational Shift
In many ways, Phia is a metaphor for Gen Z itself—ambitious, collaborative, tech-savvy, and socially conscious. It fuses the aesthetic obsession of fashion with the existential urgency of climate change and turns it into something actionable, joyful, and accessible.
Phoebe Gates and Sophia Kianni aren’t just launching an app—they’re building a movement. One thrifted crop top at a time, they’re helping a generation turn their values into style, and their style into change.
As Phia continues to grow, it may well redefine not only how Gen Z shops—but how they shape culture, climate, and commerce in the 21st century.