Block distractions. Protect your focus.
PrismBlock is a smart, privacy‑first browser extension that keeps you in flow. Choose from four blocking modes—Off, Basic, Optimal, Complete—and tailor everything with filter lists, schedules, and custom rules.
Trusted by thousands of focused users
Benefits that help you do your best work
Powerful, flexible controls that reduce friction and protect your attention.
Four blocking modes
Switch instantly between Off, Basic, Optimal, and Complete. Pick the right level for every moment.
Powerful customization
Fine‑tune PrismBlock to your needs with flexible filter lists and settings.
Enable/disable built‑in filter lists anytime.
Create custom keyword or regex pattern rules.
Tune schedules, breaks, and Pomodoro duration.
Smart overrides with short timed access windows.
Combine multiple lists to match your workflow.
Privacy‑first local data. No tracking. No ads.
How it works
Get started in minutes—results from day one.
Get PrismBlock from the Chrome Web Store.
Choose a blocking mode and enable relevant filter lists.
Set schedules, add custom keywords, and stay in flow.
Loved by focused people
Real results from real users.
“PrismBlock helped me reclaim 2+ hours a day. The nudges are just enough to keep me honest.”
“I love the four modes and quick override. It respects my intent without being rigid.”
“The insights are gold. Seeing patterns made it easy to tune my workday and stay in flow.”
100% Free. No paywall.
Everything you need for deep focus—no trials, no upsells, no ads.
Full feature set including all four modes, filter lists, schedules, and insights.
- Off, Basic, Optimal, Complete modes
- Enable/disable filter lists
- Custom keywords & patterns
- Focus schedules & Pomodoro
- Privacy‑first local data
- Lightweight & fast