Free Forever

You Shall Not Pass

The Chrome extension that keeps students on task and K-12 sysadmins sane.

Trusted on 400,000+ Chromebooks across K-12 districts

Download Extension Generate Config

Works out of the box with smart defaults - no config required.

What It Does

Students are creative. They find proxies, exploit Google Sites, spam tabs, and run games during class. You Shall Not Pass stops all of it, automatically.

🚫

Blocks Proxy Sites

Detects and blocks Ultraviolet, Rammerhead, Scramjet, Holy Unblocker, and dozens of other proxy frameworks students use to bypass your web filter.

📑

Controls Tab Spam

Enforces tab limits and detects bookmark-folder flood attacks. Automatically closes excess tabs before they crash the Chromebook.

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Google Sites Inspector

Deep-scans Google Sites pages for blob URLs, embedded game engines, Cloudflare Worker iframes, and base64-encoded content used to smuggle games.

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No Logging At All

Zero data collection, zero logs, zero telemetry. Nothing is stored, nothing is transmitted. Eliminates any FERPA, COPPA, or other privacy concerns entirely.

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Education Sites Exempted

100+ curriculum platforms are exempted by default so instruction is never interrupted. IXL, Khan Academy, Google Workspace, Quizlet, Desmos, Kahoot, and many more.

⚙️

Admin-Configurable

Push custom configs via Google Admin Console or a hosted JSON URL. Toggle individual rules, adjust thresholds, add domain allowlists and blocklists.

View all exempted education sites

Reference

  • Wikipedia
  • Britannica
  • World Book Online

Curriculum & Assignments

  • IXL
  • Khan Academy
  • EdPuzzle
  • Newsela
  • CommonLit
  • BrainPOP
  • ReadWorks
  • Nearpod
  • Pear Deck
  • Quizlet
  • Quizizz
  • Kahoot
  • Blooket
  • Gimkit
  • Formative
  • Kami
  • Flipgrid
  • Padlet
  • Seesaw

LMS Platforms

  • Google Workspace
  • Schoology
  • Canvas (Instructure)
  • Blackboard
  • PowerSchool
  • Microsoft 365
  • SharePoint / OneNote
  • Clever
  • ClassDojo
  • Remind

Math & Science

  • Desmos
  • GeoGebra
  • Wolfram Alpha
  • Mathway
  • Photomath
  • PhET Simulations

Language & Reading

  • Duolingo
  • Epic!
  • Raz-Kids
  • Starfall
  • ABCya
  • Lexia Learning
  • NoRedInk

Coding Education

  • Code.org
  • Scratch
  • Codecademy
  • Replit
  • GitHub

Testing & Assessment

  • College Board
  • ACT
  • NWEA (MAP)
  • Amplify
  • Renaissance
  • i-Ready

Research & Media

  • PBS LearningMedia
  • National Geographic
  • NASA
  • Smithsonian
  • Library of Congress
  • National Archives
  • TED
  • JSTOR
  • Google Scholar

Study & Productivity

  • Turnitin
  • Grammarly
  • Canva
  • Prezi
  • Notion
  • Lucidchart
  • EasyBib / BibMe
  • NoodleTools
  • Zotero

Higher Ed / MOOCs

  • Coursera
  • edX
  • Udemy

Why K-12 Sysadmins Love It

✓
Zero cost. Free forever. No subscriptions, no tiers, no upsells. Built by Jim Tyler as a gift to K-12 IT.
✓
Works immediately. Install the extension and the defaults handle the most common evasion tactics. No configuration required.
✓
Stays current. The rule set is continuously updated as new proxy frameworks and exploit techniques appear in the K-12 ecosystem.
✓
Respects educational sites. IXL, Khan Academy, Google Workspace, Desmos, Quizlet, Kahoot, Schoology, Canvas, PowerSchool, Clever, and 90+ more curriculum platforms are exempted by default.
✓
Enterprise-ready. Deploy and manage at scale through Google Admin Console with managed storage policies.

It's a Security Tool, Not Just a Filter

Student proxy sites and browser exploits are not just a classroom management problem. They are active security threats to your network.

Proxy Sites Expose Student Data

When students route traffic through Ultraviolet or Rammerhead proxies, their data passes through third-party servers outside your network. Credentials, personal information, and browsing activity are all exposed to unknown operators with zero accountability.

CIPA Compliance and E-Rate Funding

CIPA requires schools receiving E-Rate funding to block access to harmful content. If students bypass your web filter using proxies, your district is out of compliance and your E-Rate funding is at risk. You Shall Not Pass blocks the bypass tools themselves.

LTBEEF Disables Security Extensions

LTBEEF is a bookmarklet exploit that gives students a GUI to disable Chrome extensions, including your web filter, monitoring tools, and this extension. You Shall Not Pass detects and neutralizes the LTBEEF GUI before it can act.

Google Sites Iframe Abuse

Because sites.google.com is whitelisted by every school district, students embed proxy clients and games inside Google Sites using blob URLs, Cloudflare Workers, and base64-encoded payloads. The Google Sites Inspector catches all of these techniques.

Privacy & Compliance

FERPA Compliant

No student data is collected, transmitted, or stored. There are no logs, no server, no cloud, no telemetry. Nothing to disclose because nothing is recorded.

COPPA Compliant

The extension collects zero personal information from children. No data of any kind is gathered, stored, or shared. Full compliance by design.

Zero Data Collection

No logs, no analytics, no tracking, no storage. The extension blocks threats and moves on. Admins can optionally host a config file on their own infrastructure.

Get Started in Under a Minute

Install the extension from the Chrome Web Store, force-install it via Google Admin Console, and you're done. The defaults just work.

Download Extension Generate Config