Mysterian AI for Gmail Chrome Extension
Summarizes long Gmail threads and drafts context-aware replies from inside your inbox.
At a glance
Starts at
Free
No paid plan found on the Chrome Web Store, September 2026.
Free tier
Yes
Platforms
Chrome
Best for
Heavy Gmail users drowning in long threads
Not for
Anyone needing multi-inbox support today
3.9 out of 5
Scored by a Toolio reviewer after real useOur verdict
Mysterian sits inside Gmail and turns semantic search, thread summaries, and one-click AI replies into features you reach without leaving your inbox. You can also chat directly with your mail history to surface older context instead of scrolling back through threads. Multi-inbox management is still listed as coming soon, so if you already juggle several Gmail accounts you'll be waiting for that piece, and the extension only runs in Chrome.
✓What it does well
Semantic email searchSearch goes beyond keywords, matching by concept and context across your inbox.
Thread summarizationLong email threads get condensed into short summaries with the key points highlighted.
One-click AI repliesDraft replies are generated automatically, tailored to the specific thread you're answering.
✕Where it falls short
Chrome onlyThe extension only runs in Chrome, with no listed version for other browsers.
Single inbox for nowManaging multiple Gmail accounts is still listed as a coming-soon feature, not something available today.
Gmail-specificIt works only within Gmail, so it offers nothing for Outlook or other webmail providers.
Key features
Semantic searchSuper Semantic Search matches queries by concept rather than exact keywords.
Thread summariesIt condenses lengthy threads into short, actionable summaries.
AI composeAI Compose drafts replies tailored to each conversation in one click.
Inbox chatChat with Your Inbox lets you ask questions about your own email history.