If you use three or four AI tools regularly, you've had this problem: you remember getting a great answer somewhere last week, but you can't remember which tool you asked. Was it Claude? ChatGPT? Perplexity?
LLMnesia is a free Chrome extension that solves this by indexing your AI conversations locally and letting you search across all of them from a single search box.
The extension works with ChatGPT, Claude, Gemini, Perplexity, DeepSeek, Grok, Mistral, Kimi, Qwen, and Google AI Studio. It indexes conversations automatically as you use these platforms - no manual saving or tagging required. Search results link directly to the specific message, so you're not scrolling through long conversation threads trying to find that one paragraph.
The privacy angle is the main selling point. Everything stays in your browser's local storage. There are no accounts, no cloud sync, and no data transmitted to external servers. The extension uses standard browser permissions (storage, tabs, active tab, scripting) scoped to supported AI platforms only. You can export all indexed data with one click or delete everything just as easily.
This is a genuinely useful niche tool for heavy AI users who bounce between platforms. The built-in search in most AI tools is mediocre at best - Claude's conversation search is particularly limited - so having a unified index across ten platforms fills a real gap. The local-only storage means you're not handing another company a complete record of every question you've asked an AI, which matters more than most people realize.
The tradeoff is obvious: local-only means no cross-device sync, so your index lives and dies with that browser profile. And since the extension scrapes conversation content from each platform's web interface, it'll break whenever those platforms redesign their pages. That's the fragility built into any browser extension that depends on third-party DOM structures.
LLMnesia is free and available on the Chrome Web Store now.