SnapFull — Full Page Screenshot Extension

A Chrome extension that captures full-page screenshots and lets you export them as PNG or PDF, with a built-in screenshot history gallery.

Features

• Full-page capture — scrolls bottom-to-top, stitches viewport strips into one seamless image
• Smart scroll detection — three-tier strategy: window scroll → SPA element scroll → single frame
• Fixed/sticky element handling — nav bars and sidebars are hidden during strip capture and composited back at the top via an overlay pass (Shadow DOM-aware, works on Reddit, YouTube, etc.)
• Preview page — instant preview after capture with fit ↔ original-size toggle and pan support
• Screenshot gallery — IndexedDB-backed history with thumbnail grid, per-item PNG/PDF download, delete, multi-select batch delete
• Group by site — optional collapsible grouping in the gallery
• Lightbox — full-resolution viewer with fit/100% zoom toggle and drag-to-pan
• PNG & PDF export — available from both preview page and gallery
• Copy to clipboard — one-click copy as PNG
• Keyboard shortcut — Alt+Shift+P (Windows/Linux) / Cmd+Shift+P (Mac)

File Structure

manifest.json          Extension manifest (MV3)
background.js          Service worker: capture session, OffscreenCanvas stitching, IndexedDB history
content.js             Content script: scroll strategy, fixed-element hiding, strip coordination
popup.html/css/js      Extension popup (trigger capture, open gallery, shortcut hint)
preview.html/css/js    Post-capture preview page
gallery.html/css/js    Screenshot history & management page
icons/                 Extension icons (16/32/48/128 px)
libs/
  jspdf.umd.min.js     jsPDF for client-side PDF generation

Installation (Developer Mode)

1. Clone or download this repository
2. Open Chrome → chrome://extensions
3. Enable Developer mode (top-right toggle)
4. Click Load unpacked and select this folder
5. The SnapFull icon appears in your toolbar

Usage

• Click the SnapFull icon in the toolbar → Capture
• Or use the keyboard shortcut (Alt+Shift+P / Cmd+Shift+P)
• After capture, a preview tab opens automatically
• Click History in the preview toolbar or popup to open the gallery

Technical Notes

• Capture is done with chrome.tabs.captureVisibleTab per strip; strips are composited on an OffscreenCanvas in the service worker
• Thumbnail generation uses a second OffscreenCanvas (JPEG 72%, max 300 px wide) to keep IndexedDB storage lean
• Fixed/sticky elements are tagged with data-snapfull-hide and hidden via a CSS rule with !important (covers descendants) before strip capture; restored afterward with one overlay capture drawn at canvas origin
• SPA pages (element-scroll mode) use containerBounds to draw only the scrollable content area at each offset, plus a single outer-frame draw at y=0

Version

v1.0 — initial release