Tools: I Built a Chrome Extension That Captures YouTube Screenshots at Custom Intervals (Even 10+ Hour Videos)

Key Features ## How It Works (Technical Deep Dive) ## What I Learned Building This ## Installation (Dev Mode) ## 🤝 Contributions Welcome ## 🌟 Final Thoughts ## 📸 Screenshots Ever wanted to automatically capture screenshots from a YouTube video every 10 seconds? Or extract frames from a 3-hour lecture without manually pausing and screenshotting hundreds of times? I built a Chrome extension to solve exactly that. YouTube Screenshot Capture Give Star To My Repo GitHub: https://github.com/akshitsutharr/Youtube-Screen-capture Capturing screenshots manually from long YouTube videos is extremely inefficient: For students, researchers, analysts, and creators — this wastes hours. So I built a solution. This Chrome Extension allows you to: All processing happens locally inside your browser. No servers. No data collection. No API keys. Supports both formats: Capture screenshots every: Smart Chunking (Large Video Support) For videos longer than 1 hour: The extension automatically splits processing into 1-hour chunks to prevent: This makes it capable of handling 10+ hour videos efficiently. Each capture session downloads: For long videos: Multiple ZIP files are generated (one per hour chunk). Real-Time Progress Tracking No guessing. No silent processing. The extension injects a content script that: Seeking to Specific Timestamps The extension waits for the seeked event before capturing. Capturing Frames via Canvas API Intelligent Chunking Logic To avoid memory crashes: Performance Optimizations 360 screenshots ≈ 2–3 minutes Privacy & Permissions Permissions required: Everything runs locally. This project helped me deeply understand: Handling very large videos safely without crashing Chrome. Chunking logic solved that. If you're interested in: 🔗 GitHub: https://github.com/akshitsutharr/Youtube-Screen-capture This started as a small productivity tool. But it turned into a deep dive into: Templates let you quickly answer FAQs or store snippets for re-use. Are you sure you want to hide this comment? It will become hidden in your post, but will still be visible via the comment's permalink. Hide child comments as well For further actions, you may consider blocking this person and/or reporting abuse CODE_BLOCK: video.currentTime = timestamp; Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: video.currentTime = timestamp; CODE_BLOCK: video.currentTime = timestamp; CODE_BLOCK: const canvas = document.createElement("canvas"); const ctx = canvas.getContext("2d"); ctx.drawImage(video, 0, 0, width, height); Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: const canvas = document.createElement("canvas"); const ctx = canvas.getContext("2d"); ctx.drawImage(video, 0, 0, width, height); CODE_BLOCK: const canvas = document.createElement("canvas"); const ctx = canvas.getContext("2d"); ctx.drawImage(video, 0, 0, width, height); CODE_BLOCK: canvas.toBlob(...) Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: canvas.toBlob(...) CODE_BLOCK: canvas.toBlob(...) CODE_BLOCK: const CHUNK_DURATION = 3600; // 1 hour Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: const CHUNK_DURATION = 3600; // 1 hour CODE_BLOCK: const CHUNK_DURATION = 3600; // 1 hour - Pause → Screenshot → Play → Repeat - No batch export - No timestamp organization - Hard to manage large videos - Impossible to scale for 2–10 hour content - Capture screenshots from any custom time range - Set intervals from 1 second to 1 hour - Automatically chunk videos longer than 1 hour - Download all images as ZIP files - Track progress in real time - Choose screenshot quality (High / Medium / Low) - Start: 00:01:20 - End: 00:09:23 - Up to 1 hour - Memory overflow - Browser crashes - Performance drops - All screenshots in JPEG format - Organized by timestamp - info.txt file with capture details - Percentage completed - Screenshot count - Processing updates - Manifest V3 - Chrome Storage API - Chrome Downloads API - Detects the <video> element - Ensures it is playable - Controls playback programmatically - Captures screenshots - Packages them into ZIP - Triggers download - Frees memory - Continues to next chunk - Video auto-mutes - Playback pauses for frame stability - UI updates are throttled - Object URLs are cleaned - Memory is released per chunk - host_permissions (only youtube.com) - No data leaves your browser - No tracking - No analytics - No external servers - Chrome Extension architecture (Manifest V3) - Content scripts vs background service workers - Canvas-based video frame rendering - Browser memory management - Large file processing inside the browser - Async UI state control - Clone repository - Go to chrome://extensions - Enable Developer Mode - Click "Load Unpacked" - Select project folder - Chrome Web Store release - Preset capture profiles - Automatic keyframe detection - Video metadata export - PDF storyboard export - Chrome extension development - Performance optimization - UI improvements - Feature additions - Browser APIs - Video processing - Performance en