Summarize YouTube videos instantly — right from your browser.
Skip the video, keep the value. With one right-click or through the extension popup, Briefly pulls the transcript for the current YouTube video. It can copy the transcript to your clipboard or auto-summarize it using Google’s Gemini in AI Studio. Perfect for research, note-taking, or just staying informed — without the watch time.
| Action | What happens |
|---|---|
| Get & Copy Transcript | Uses a bundled JavaScript library (based on youtube-transcript-api) directly in the extension → fetches the full transcript (with preferred language logic) → copies it to your clipboard via Chrome’s Offscreen API. |
| Summarise in AI Studio | Same transcript fetching method → opens aistudio.google.com → pastes a pre-defined prompt + transcript → attempts to selects preferred model → disables/enables preferred “Thinking mode” → clicks Run. |
| Feature | info |
|---|---|
| Popup Interface | Access core actions (copy, summarize) for the active YouTube tab directly from the extension icon. |
| Robust notifications | API / network / automation errors bubble up clearly. |
| Cross-platform | works on Chrome, Edge, Brave, etc. (Manifest v3). |
git clone https://github.com/labib2002/briefly.git
cd briefly- Open
chrome://extensions(or the equivalent for your browser, e.g.,edge://extensions). - Turn on Developer mode.
- Click Load unpacked → select the
brieflyproject folder (the one containingmanifest.json).
- Navigate to a YouTube video page (
youtube.com/watch?...,youtu.be/...,youtube.com/shorts/...). - Option 1: Context Menu
- Right-click any YouTube video link on a webpage.
- Choose:
- Briefly: Get & Copy Transcript Text
- Briefly: Automate Summary in AI Studio
- Option 2: Extension Popup
- While on a YouTube video page, click the Briefly extension icon in your browser toolbar.
- Click either Copy Transcript or Summarize in AI Studio.
- Read the notification that appears. If you picked AI Studio, switch to the new tab and watch Gemini work its magic.
| File | What to tweak |
|---|---|
background.js |
PREFERRED_LANGUAGES array, promptText template for AI Studio, AI Studio automation time-outs. |
content_script_aistudio.js |
CSS selectors for AI Studio elements & default model name string (e.g., "Gemini 2.5 Flash Preview"). |
| Symptom | Likely cause / fix |
|---|---|
| Transcript unavailable / error fetching transcript | Uploader disabled transcripts, no transcripts in your PREFERRED_LANGUAGES (see background.js), or a temporary YouTube issue. Check the Service Worker console. |
| Automation stalls or fails in AI Studio | Google’s AI Studio UI might have changed – adjust selectors in content_script_aistudio.js. Use DevTools console in the AI Studio tab to inspect errors. The target model ("Gemini 2.5 Flash Preview") might also be unavailable or renamed. |
| Clipboard error | Rare; open the extension’s Service worker console in chrome://extensions for details. |
| Buttons in popup are disabled | Ensure you are on an active YouTube video page (youtube.com/watch, youtu.be, youtube.com/shorts). |
- Service worker logs (for background tasks, transcript fetching) →
chrome://extensions→ find Briefly → click Service worker. - Content-script logs (for AI Studio automation) → Open DevTools (F12) console in the AI Studio tab.
- Popup logs (for popup UI issues) → Right-click the extension icon → Inspect popup → Console tab.
- Direct Gemini API Integration – Add option for Google’s public Gemini API (or Vertex AI) directly, bypassing AI Studio UI automation for a faster and more reliable summarization.
- Enhanced Popup / Options UI – Allow users to customize preferred languages, edit the AI Studio prompt, select different summarization models, and toggle other features through a dedicated options page or an enhanced popup.
- Process Current Video via Popup – One-click actions in the extension popup to process the video in the active tab (Implemented in v1.4).
- Standalone Application – Package Briefly as a desktop application, removing the need for a browser extension (e.g., using Electron or similar).
- Local LLM Support – Send transcripts to a locally running LLM (e.g., via Ollama / GGUF models) for offline summaries.
- Internationalisation (i18n) – Translate extension UI text and default prompts into multiple languages.
- Customizable Summarization Profiles – Allow users to define and switch between different summarization styles or lengths (e.g., "brief overview," "detailed points," "key takeaways").
- Support for more video platforms – Extend transcript and summarization capabilities to other platforms beyond YouTube.
Pull-requests welcome – open an issue first so we don’t duplicate work!
- Fork → branch → PR (use Conventional Commits).
- First-timers welcome – check good-first-issue.
Released under the MIT License – see LICENSE.md.
The core logic for fetching YouTube transcripts is derived from the excellent youtube-transcript-api Py library, adapted for direct use within the browser extension.