Voice of Reason

Inspiration

We’ve all been there: halfway through a compelling video about health, finance, or global politics, wondering, "Is this actually true?" YouTube is the world's second-largest search engine, yet it remains a frontier for unchecked misinformation. Unlike platforms with Community Notes or news articles that can be easily cross-referenced, video content is often "locked." Manually pausing a video to search for a creator's claim is tedious and breaks the viewing experience. We built Voice of Reason to bridge that gap, providing a real-time "truth layer" over the videos we consume daily.

What it does

Voice of Reason is a Chrome extension that acts as an AI-powered moderator for your YouTube experience.

Check This Moment: With a single click (or ⌘⇧V / Ctrl+Shift+V), the AI analyzes the last 60 seconds of the video to verify the specific claim you just heard.
Full Video Analysis: Scans the entire transcript to generate a comprehensive report of all major claims.
Visual Verdicts: Claims are tagged as TRUE, FALSE, or MISLEADING with concise reasoning and citations.
Interactive Timestamps: Click any claim in the report to jump directly to that moment in the video.
Authenticity Score: Provides an overall "Trust Rating" for the video based on the ratio of verified vs. debunked claims.
Deep Dive Chat: Not satisfied? Use the built-in chat to ask follow-up questions about the sources or context directly within the extension.

How we built it

We combined a high-performance Python backend with a reactive Chrome frontend:

The Brain: We leveraged the Perplexity API to perform live web searches. Its ability to cite real-time sources makes it the gold standard for fact-checking.
The Bridge: A Flask (Python) backend handles the heavy lifting, using the YouTube Transcript API to fetch and parse dialogue data based on timestamps.
The Interface: A JavaScript/HTML/CSS extension UI that injects seamlessly into the YouTube player, ensuring the data is right where your eyes are.
Structured Parsing: We designed custom prompts to force the LLM to return structured JSON data, ensuring our UI could accurately map verdicts to the video timeline.

Challenges we ran into

The "No Caption" Conundrum: Not all videos have manual or auto-generated captions. We built robust error handling and fallback states for when data is unavailable.
The Latency Race: Fact-checking requires a live web search, which can be slow. We optimized our processing by "chunking" transcripts so Perplexity could begin analyzing relevant sections without waiting for the whole video to load.
Cross-Context Messaging: Coordinating data between the background script (handling the API), the content script (talking to the YT player), and the popup (the UI) was a complex exercise in asynchronous logic.

Accomplishments that we're proud of

We successfully built a tool that doesn't just "summarize"—it investigates. Seeing the extension successfully debunk a common health myth in real-time and provide a link to a peer-reviewed study felt like a "eureka" moment for the future of media literacy. It was also fulfilling to see our project com to life as first-time hackers.

What we learned

We learned that "truth" is often nuanced. We spent significant time refining our prompts to ensure the AI doesn't just label everything "False," but instead recognizes misleading contexts or partially true statements, providing a balanced perspective rather than a binary one.

What's next for Voice of Reason

Platform Expansion: Bringing the "Voice of Reason" to TikTok, Instagram Reels, and podcasts.
Community Integration: Allowing users to "Upvote" or "Downvote" fact-checks to create a decentralized layer of trust.
Mobile Support: Developing a mobile browser version or a dedicated "Share to Fact-Check" app.
Multi-language Support: Breaking the language barrier to fact-check non-English content in real-time.