About 404 Privacy
Privacy is the freedom to explore without being followed.
404 Privacy builds software, conducts assessments, and publishes research to help people understand and reduce the signals that make them recognizable online.
The name
Why 404?
On the web, 404 means “Not Found”: the server could not find the requested resource.
For 404 Privacy, the name expresses an ambition: people should be able to explore the web without being readily found, profiled, and followed through the signals they leave behind.
It is a statement of purpose. Our work is to reduce unwanted recognition and give people greater control over what their online activity reveals about them.
Purpose
Our mission
I want people to have more control over when their activity becomes connected to their identity.
The ability to research, ask questions, form relationships, and change your mind matters. When those activities become material for persistent profiling, the consequences reach beyond advertising. They can affect what people feel safe reading, saying, or doing—and expose the people they work with.
Privacy protects the space people need to think and act freely.
I built 404 to address the data a browser and device reveal simply by connecting to a website—signals that can remain recognizable even when someone changes their IP address, clears their cookies, or opens a private window.
My mission is to make that exposure understandable, measurable, and harder to exploit. That means building practical tools and helping people make informed decisions about the tools they use to ensure their online safety.
Seth Honda Founder
The work
Turning that mission into practical work
404 brings engineering, measurement, and education together.
Software
Give people greater control over the fingerprint signals their browser and device present.
Explore the softwareAssessments and consulting
Help organizations understand what remains recognizable across their working environments and prioritize practical changes.
Explore the servicesResearch and education
Explain how tracking works, examine the systems behind it, and make technical privacy knowledge accessible to the people affected by it.
Read the researchTwo promises across our work
- Local-first architecture
- Genuine minimal data collection
Open source
People should be able to examine the tools they rely on.
404’s core software is open source. Its implementation is available for people to inspect, test, question, and improve under the applicable licenses.
That openness matters for privacy software. People should be able to understand how a tool handles their traffic, what it changes, and where its protections end. Researchers and developers should be able to investigate its behavior and challenge its claims.
Publishing the implementation makes scrutiny part of the work. Documentation, testing, and public research help make that scrutiny useful.
The people behind the work
Team
Seth Honda
Founder
Seth builds the software, leads privacy assessments, and develops 404 Privacy’s research and educational work.
His background spans software development, computational research, and teaching. Alongside 404, he teaches computer science and literature—a combination that informs both the engineering and the effort to make complex systems understandable.
404 Privacy is based in Colorado Springs, Colorado.