Scan history
Keep a visual record of what changed across commits, branches, and release candidates.
fossilA clearer view of your product.
fossil maps your app's screens, states, flows, and visual changes in one local interface.
Version comparison
Compare responsive layouts and scan versions side by side before you ship.
Flow maps
Visualize the paths users can take through your product instead of reviewing screens in isolation.
Make product decisions with fewer blind spots.
See your interface clearly before choosing what to improve next.
See the full surface
Screens, states, flows, and changes stay visible together.
Find UX weak spots
Spot stale states, awkward journeys, drift, and forgotten surfaces.
Decide with context
Return to evidence instead of memory or scattered screenshots.
Launch pricing
Local License. One-time payment.
Try every local feature free for 7 days. No card required.
Local License
Pay once when you’re ready. No subscription.
€44.50€8950% launch discount
- One-time local desktop license
- No subscription and no required account
- Private target projects stay on your machine
- Inspect your app graph and captured states
- Compare layouts across viewports
- Compare scan versions over time
Frequently asked questions
How does the free trial work?
Download fossil, then start a full-featured 7-day free trial from the desktop app. No card or fossil account is required, scans are unlimited, and one free trial key works on one device. There is no automatic charge, and your local projects and scan history remain preserved when the free trial ends.
What data leaves my machine?
Your target projects stay local by default. fossil analytics does not collect source code, project files, filesystem paths, command output, server logs, screenshots, secrets, license keys, or target-project content. If you connect an AI agent, fossil shares the bounded task context that agent needs for the workflow you started.
Will fossil work with my stack?
fossil is built for web projects you can open or run in a browser, whether it is your product, a client app, an internal tool, or another project you need to inspect. Point fossil at a project with a preview command or reachable URL, and it maps the screens and states it can access.
Can I connect fossil to any AI agent?
Yes, if the agent supports MCP. Codex has the most integrated flow in fossil, but you can also connect MCP-capable agents by adding fossil as a local stdio MCP server, then letting the agent request bounded project and exploration context.
Will fossil change files in my project?
No. fossil reads your selected project without writing to it and only runs a preview command you explicitly approve. Its database, scan history, screenshots, and temporary files stay in fossil's local app data, outside your project.
Are team features coming?
Yes. The first release focuses on the local desktop workbench, and a cloud subscription is planned for teams that need to sync fossil data across people, projects, branches, and review workflows.
Start your free trial.
Explore every local feature for 7 days. No card and no account required.