SafeBrowse — Privacy-first Web Safety Extension

SafeBrowse is a lightweight, on-device browser extension that helps families, schools, and workplace teams reduce exposure to harmful content without compromising privacy. Built and maintained by CyberHeroez CIC.

Features

• Advanced heuristics: weighted URL/title/meta/body scoring with sensitivity control
• On-page protection: optional Aggressive mode to blur/pause images/videos on-device
• Visual detection: image heuristics sample pixels to escalate or block graphic imagery even without text
• Domain blocklist: packaged defaults + user-importable list; allowlist overrides
• Sensitivity profiles: Kids (7-12), Teens (13-16), College, and Work presets tuned for safeguarding and productivity goals
• Explain why this was blocked: interstitial gives kid-friendly reasoning, safe suggestions, and rotating AI literacy micro-lessons
• Family setup wizard: 30-second onboarding for age presets, PIN, and Focus defaults
• Conversation starters: parent card with topic-only scripts when content is blocked (no URLs stored)
• Kid reports: “Report unsafe page” button (host + optional note, stored locally, PIN-gated view)
• Healthy nudges: gentle break reminders and wellbeing prompts, all on-device
• Weekly tips: local digital-safety tips delivered once per week
• Focus Mode: homework/study timer that blocks social/gaming/streaming and allows edu sites
• Classroom Mode: teacher lockdown (social/gaming blocked, YouTube playlists only, overrides locked)
• SafeSearch enforcement: redirects Google/Bing to strict modes (DNR)
• Control centre: refreshed popup with live status badge, quick toggles, and policy management in one place
• First-run tour: onboarding highlights key controls and policy workflows for new admins
• Static ad rules: common ad/marketing domains blocked via DNR
• PIN protection: require a PIN before overrides or allowlist edits, capturing on-device reason & approver logs
• Secure alerts: HTTPS-only override/tamper webhooks (no localhost/LAN/creds) with PIN-locked setup
• Safeguarding digest: export a weekly CSV summary of settings and override activity for DSL reviews
• Override alerts: optional PIN-protected webhooks (Slack/Teams/email) with approver names for instant oversight
• Encrypted override log: AES-GCM at rest; stores timestamp, host, reason, and approver only (no full URLs)
• Interstitial: blocked page with timed “Show anyway” override (per tab/session)

Business-ready capabilities

• Privacy by design: all analysis and decisioning stays on-device; no browsing data is transmitted.
• Policy controls: organisation-wide allowlists & custom blocklists with import/export workflows.
• Deployment friendly: minimal permissions (storage, declarativeNetRequest) and no background polling.
• Support collateral: ready-made privacy policy, security briefing (SECURITY.md), support workflows (SUPPORT.md), UK safeguarding packs (docs/KCSIE_COMPLIANCE_MATRIX.md, docs/PREVENT_DUTY_BRIEFING.md, docs/DPIA_TEMPLATE_UK.md), and age-based profile presets.
• Managed Chrome guidance: see docs/WEBSTORE.md for publishing, docs/DEPLOYMENT.md for rollout playbooks, and SUPPORT.md for help desk scripts.

Hosted resources

• Bundled static pages (packaged inside the extension): site/index.html, site/privacy.html, site/support.html
• Optional public hosting: host site/ on cyberheroez.co.uk (or enable GitHub Pages) and point the Chrome Web Store listing + homepage to those URLs.

Browser support

• Chromium browsers (Chrome/Edge/Brave/Vivaldi/Opera): load the repo folder directly (contains manifest.json).
• Firefox: build and load dist/firefox/manifest.json (see docs/BROWSER_SUPPORT.md).
• Safari: convert via Apple’s Safari Web Extension tooling (see docs/BROWSER_SUPPORT.md).

Dev Setup

1. Chrome → chrome://extensions → enable Developer mode
2. Load unpacked → select this folder
3. Open the popup → toggle Enable protection (badge shows Active)
4. Optional: toggle Aggressive mode and adjust Sensitivity
5. Optional: paste domains (one per line) into Blocklist → Import/Replace
   • or edit data/blocklist.json and reload the extension
6. For private windows: open extension details → enable Allow in Incognito

Quick setup (parents)

1. Enable protection in the popup.
2. Run the Family Setup Wizard → pick age profile → set PIN (for overrides) → set Focus default.
3. Turn on Conversation starters and Weekly tips (optional).
4. Show your child the “Report unsafe page” button; review reports in Parent mode.

Quick setup (teachers)

1. Enable protection; apply Classroom Mode when teaching.
2. Add approved YouTube playlists/videos if needed; overrides stay locked.
3. Use Focus Mode presets for study blocks; allow comms tools only if required.
4. Review Child reports/Overrides in Parent mode (PIN-gated).

Privacy/Security at a glance

• All analysis runs locally; no browsing history or page content is sent anywhere.
• Kid reports store only timestamp + host + optional note; conversation starters store topic only.
• Override logs are encrypted locally; webhooks require HTTPS and no LAN/localhost.
• Web-accessible resources are limited; SafeSearch and DNR rules enforced; PIN hashes are salted/iterated.

Notes:

• Content script is src/content.js (manifest aligned). The legacy content.js remains in repo but is not loaded.
• Permissions: storage, declarativeNetRequest, tabs; scripts run on http/https pages only (tabs permission is used to show the active site toggle).
• Web-accessible resources limited to https://*/* (no localhost/LAN) to reduce fingerprinting.
• DNR rules are rebuilt on install/startup and when allowlist/blocklist change.
• Interstitial uses safe DOM APIs; “Show anyway” temporarily allows the current host for this tab/session.

Roadmap

• On-device visual model (optional) for stronger image/video detection
• Options page polish + export/import lists (popup import exists)
• Scheduled safeguarding digests and trust-level preset sharing
• Chrome Web Store listing (screenshots, description, privacy link)

MIT License

Quick start

1. Load unpacked (Developer mode)
2. Toggle Enable protection in the popup (status badge turns green)
3. Optional: toggle Aggressive mode + set sensitivity
4. Blocklist: paste domains → Import/Replace (one per line)
5. Visit sites to verify interstitial (strong signals) or blurring (contextual)

Phase 1 additions

• Static DNR rules for common ad domains and SafeSearch (Google/Bing)
• Dynamic DNR rules compiled from packaged + user-imported blocklist with allowlist overrides
• Focus Mode timer with edu allowlist + social/gaming/streaming blocks
• Classroom Mode lockdown for teachers (overrides disabled; YouTube playlists only)
• Conversation starters, weekly tips, healthy nudges, and kid reports (host-only, optional note)

Limitations

• Chrome’s dynamic DNR rules have capacity limits (~30k). Very large custom imports are truncated.
• Visual detection is heuristic-based; cross-origin videos may block pixel reads (skipped).

Community

• Code of Conduct: see CODE_OF_CONDUCT.md
• Contributing guide: see CONTRIBUTING.md
• Security policy: see SECURITY.md (report via GitHub advisories)
• Support: see SUPPORT.md
• Publisher: CyberHeroez CIC — https://cyberheroez.co.uk/
• Maintainer: dipesthapa (dipesh@cyberheroez.co.uk)

Chrome Web Store

• Publishing workflow: see .github/workflows/publish-webstore.yml
• Setup + credentials + manual upload steps: docs/WEBSTORE.md
• Listing content template: docs/STORE_LISTING.md
• Build zip for upload: npm run zip:webstore (outputs dist/extension.zip; ensures only required files are packaged)