Browser Guard

Browser Guard is a Manifest V3 Chrome extension scaffold for reducing browser friction. It prevents duplicate tabs, organizes open tabs, replaces the default new-tab page with a clean search page, nudges Google searches into Web results mode, captures full-page screenshots, records screen video locally, forces dark mode, saves direct media files, boosts tab audio, and blocks distracting sites.

Original author: Roberto Moreno.

Features

• Auto-closes duplicate HTTP/HTTPS tabs as they open or finish loading.
• Preserves route-like URL fragments for single-page apps such as the AWS console while ignoring ordinary page anchors.
• Keeps Browser Guard's own new-tab page from duplicating.
• Manual duplicate cleanup from the popup.
• Sorts the current window or all normal windows.
• Merges all normal browser windows into the current window.
• Groups matching domains into Chrome tab groups and places grouped tabs before single pages.
• Tracks tab creation time from the moment the extension sees a tab.
• Keeps pinned tabs protected by default.
• Replaces Chrome's default new-tab page with a clean search page.
• Shows Browser Guard tab actions in the new-tab page top menu.
• Lists current-window tabs on the new-tab page for quick switching.
• Redirects ordinary Google searches and AI Mode search URLs to Google Web results with udm=14.
• Hides common Google AI Overview and AI Mode blocks on Google results pages.
• Captures the active page as a full-page scrolling PNG screenshot.
• Records a user-selected screen, window, or tab as a local video file with optional system/tab audio and microphone audio.
• Forces Dark Reader-style dark mode on HTTP/HTTPS pages with brightness, contrast, sepia, and excluded-site controls.
• Finds downloadable direct video/audio files on the active page and shows an in-page Download overlay on supported videos.
• Blocks configured distracting websites during work hours or after a per-site daily time limit.
• Includes immediate blocking, strict mode, and a timed Nuclear Option that locks strict blocking until the timer ends.
• Automatically resumes a blocked tab's original URL when the blocking timer or schedule no longer applies.
• Shows current time, unblock countdown, and a clearly labeled five-minute bypass on blocked pages.
• Boosts active-tab media volume up to 600% and adds bass boost up to 24 dB.
• Shows currently audible tabs in the popup for quick switching.

Load Locally

1. Open chrome://extensions.
2. Turn on Developer mode.
3. Click Load unpacked.
4. Select this folder: /Users/robertomoreno/Documents/New project.

Validate And Package

Run the extension checks:

npm run validate

Create a Chrome Web Store ZIP:

npm run package

The package is written to dist/browser-guard-<version>.zip.

Chrome Web Store And Open Source

• Store listing copy, permission justifications, privacy disclosure draft, and reviewer test steps live in docs/store-listing.md.
• The release process lives in docs/release-checklist.md.
• The public privacy policy is PRIVACY.md.
• Contributing, security, code of conduct, and issue templates are included for an open-source GitHub repo.

Notes

Chrome does not expose historical tab creation time to extensions. Tabs that were already open before Browser Guard starts are assigned a first-seen timestamp; newly opened tabs get an accurate created timestamp from that point forward.

Chrome extensions cannot directly toggle chrome://flags, write enterprise policies, or remove native omnibox UI. Browser Guard handles the extension-controlled layer: custom new tab, search-result cleanup, dark mode, focus blocking, and tab management. See docs/chrome-ai-mode.md for the native Chrome layer.

Media Saver scans normal HTTP/HTTPS pages, including YouTube and X pages, for direct media file links such as .mp4, .webm, .mov, .mp3, and .wav. When a visible video has a direct downloadable candidate, Browser Guard shows a small in-page Download overlay. On X/Twitter, it also keeps a local sanitized list of video variants exposed by X page API responses, then shows the best MP4 plus a quality menu when multiple variants are available. It does not decrypt DRM media or require private credentials.

Screen Recorder opens a dedicated extension window, asks Chrome to capture a user-selected screen/window/tab, records locally with the browser MediaRecorder API, and saves the finished file through Chrome downloads. Recordings are not uploaded by Browser Guard.

The extension asks for activeTab, alarms, downloads, offscreen, search, scripting, tabCapture, tabs, storage, and tabGroups permissions so it can read tab URLs for duplicate detection, search cleanup, audio tab detection, and focus blocking; run new-tab searches through Chrome's default search provider; scroll and capture the active page after the user clicks Web Capture; record a user-selected screen/window/tab after the user starts Screen Recorder; save screenshots, local screen recordings, and selected direct media through Chrome downloads; capture and replay active-tab audio for volume/bass controls; track time limits; persist preferences; reorder tabs; merge windows; create domain groups; and sync dark mode onto already-open tabs. It injects content scripts on HTTP/HTTPS pages for dark mode and Google search cleanup.