San Francisco's skyline transforms each December through light.
Let's Glow SF returns from December 5 to 14, 2025, bringing the nation's largest free holiday projection arts festival back to downtown San Francisco. Eight buildings transform into colorful canvases nightly from 5:30 PM to 10:00 PM, featuring animated projections by 17 artists from around the globe. This all-ages, family-friendly event is free of charge. Show up and experience the projections.
Opening Night Highlights (December 5): Join the Countdown to Glow kickoff ceremony at Harry Bridges Plaza in front of the Ferry Building, starting at 6:00 PM. Get free hot chocolate, watch a holiday performance by Gap Inc., and see city officials "flip the switch" at 7:00 PM after Glow runs at the Ferry Building South Plaza from 5:00–8:00 PM with festive music, complimentary hot beverages, and a silent disco before exploring all eight buildings.
For five years, Let's Glow SF has combined projection technology, artistic vision, and urban architecture. What started as an experiment in 2021 now draws serious numbers. Last year's festival drew 87,500 visitors across ten nights and generated $13.2 million in economic impact for downtown businesses. The transformation goes deeper than revenue.
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Projection mapping requires an understanding of the geometry, texture, and the story each structure wants to convey.
A3 Visual has been the technical architect behind every edition of Let's Glow SF since day one. We scout buildings, design projection layouts, curate artists, and handle installation to teardown.
The process starts months before the first projection lights up. Each building presents different challenges.
We use Panasonic's high-brightness projectors paired with Modulo Pi media servers. The technology matters. The creative vision transforms technical specs into experiences people remember.
Light festivals exist worldwide. Berlin's Festival of Lights attracts 3 million visitors over ten nights. Sydney's Vivid Festival attracts 2.4 million visitors across 28 nights. Lyon's Fête des Lumières draws 1.8 million in three nights.
One significant element of Let's Glow SF is that it is free to attend. Families walk from installation to installation without planning or budgeting.
This decision shapes everything. The festival becomes part of the city's fabric.
Four years of growth in numbers:
2021: 3 buildings, 40,000 visitors, $2.2 million in additional business revenue. 2025: 8 buildings, 87,500 visitors (2024 figures), $13.2 million in economic impact.
The festival more than doubled its physical footprint while growing its economic impact sixfold.
Aggregate numbers miss the human element. Downtown SF Partnership surveys show that 62% of local businesses report the festival helps their bottom line during slower periods.
Restaurants stay open later. Retail shops are seeing foot traffic they haven’t experienced since before the pandemic—hotels are booking rooms for festival visitors.
The festival proved something city planners have tried to solve for years: people come downtown at night when you give them a reason.
Technology enables the experience. Artists create the experience.
Each year, we bring together local creators and international collectives. The selection process balances established names with emerging talent. We look for artists who understand how to work within the constraints of architectural projection while pushing creative boundaries.
A flat screen and a building facade require different approaches to storytelling. Movement, color, and timing all change when your canvas is 30 stories tall.
I think part of the best installations is also people sharing the experience with family, loved ones, friends and coworkers in person, which is the essence of a light festival, togetherness. Containing the best installation parameters in a social media post, I think, misses the SF-focused/community aspect.
Running the same festival annually reveals patterns you miss in year one.
Weather matters more than expected. December in San Francisco means unpredictable conditions. We have learned to design systems for fog, rain, and wind.
Early years saw people treating installations as photo opportunities. Now a days we are seeing longer dwell times. People watch full content loops. They bring friends back on different nights.
The festival has become a tradition. Traditions keep cities alive. These are the experiences people mark on calendars and plan around.
Here's what makes large-scale projection mapping work.
You need projectors that are strong enough to overcome ambient city lights. You need media servers to handle complex mapping geometries without lag.
Then the logistics. Power requirements for eight simultaneous installations across multiple districts. Weatherproofing equipment for ten consecutive nights. Backup systems for when something fails.
A3 Visual handles all of this because we have built the necessary infrastructure and expertise over the years through our work in this area. Owning equipment is one thing. Knowing how to deploy the equipment in real urban environments is another key aspect.
The partnership model makes Let's Glow SF a sustainable organization. The Downtown SF Partnership fosters community connections and cultivates business relationships. A3 Visual brings technical capability and creative curation. Sponsors like Panasonic contribute technology and resources.
Nobody tries to extract maximum profit. The goal is to create value for the entire downtown ecosystem.
When businesses see direct benefit, they support the festival. When residents experience something special, they become advocates. When artists get a platform to showcase work at this scale, they bring their networks.
This builds momentum over time.
Five-year anniversaries create natural moments for reflection. We are more interested in what's next.
This year brings new building selections, upgraded projection systems, and fresh artistic collaborations. We are not trying to make the festival bigger for the sake of scale. We are working to improve the festival.
Better means more nuanced storytelling. Better means technical improvements that most people will not notice. Better means finding ways to surprise audiences while continually looking for more efficient and cost-effective ways to do the same, and more work.
Let's Glow has proven the model works. Now the question is how far we push the model while maintaining what makes the festival special.
Projection mapping festivals represent something larger than entertainment.
They demonstrate that public art does not require permanent installation or massive construction budgets. They show that technology creates experiences for communities.
Let's Glow SF transforms how people see their own city. Buildings they walk past every day become storytelling devices. Spaces that feel purely functional reveal creative potential.
This shift in perception matters. The shift changes the conversation about what urban spaces are and who they serve.
After five years, the festival has become part of San Francisco's identity. You cannot manufacture or force this. The shift happens when you consistently deliver authentic and valuable experiences.
We are already planning year six.