Every option in the catalog for when you need to put an AI sidebar on every website you visit — 11 AI browser extensions, 11 of them free or freemium, with the pricing tier printed on every row.
Flocci AI Tools lists 11 of them, ordered free tiers first: Firefox Smart Window, Gemini in Chrome, Opera Browser AI (Aria), Page Assist and MaxAI.me. Every one of them is free or has a free tier. Each entry states what it uniquely does rather than a score.
4 on this page are marked fully free with no paid plan at all: Firefox Smart Window, Gemini in Chrome, Opera Browser AI (Aria) and Page Assist. The remaining 7 are freemium, trial or paid, and each is labelled with its exact tier so nothing surprises you at sign-up.
Free tools first, then freemium, then trial, then paid, and alphabetically inside each tier. Nobody pays to appear higher: Flocci AI Tools carries no ads, no sponsored slots and no paid listings, so the order reflects price and nothing else.
MaxAI.me, Merlin AI, Monica and Sider all work in a browser tab with no install needed — just open the site and go. 4 of the 11 free AI browser extensions listed here are browser-based.
Gemini in Chrome, MaxAI.me, Merlin AI, Monica and Sider support Google sign-in, so you can start without creating a new account. That's 7 of the 11 free AI browser extensions on this page.
Opera Browser AI (Aria), Merlin AI, Monica, Sider and Brave Leo have an iOS or Android app. 5 of the 11 free AI browser extensions here can run on your phone.
Firefox Smart Window, Gemini in Chrome, Opera Browser AI (Aria), Page Assist and Brave Leo can be self-hosted or run locally without a browser — useful for privacy, air-gapped networks, or avoiding API rate limits. 6 of the 11 free AI browser extensions here run offline.
| Tool | Pricing | Type | Listed for |
|---|---|---|---|
| Firefox Smart Window | Free | Browser Extensions & Copilots | Built-in Firefox AI assistant that answers questions about the page and open tabs and searches browsing history in natural language |
| Gemini in Chrome | Free | Browser Extensions & Copilots | Gemini side panel that answers questions about the current tab and across tabs |
| Opera Browser AI (Aria) | Free | Browser Extensions & Copilots | Free, native AI assistant built into Opera's mainstream and GX browsers, no separate app needed |
| Page Assist | Free | Browser Extensions & Copilots | Open-source (MIT) sidebar and ChatGPT-style web UI for local models via Ollama, LM Studio or Chrome's built-in Gemini Nano |
| MaxAI.me | Freemium | Browser Extensions & Copilots | One-click rewrite, reply and summarize |
| Merlin AI | Freemium | Browser Extensions & Copilots | Works on any website |
| Monica | Freemium | Browser Extensions & Copilots | All-in-one AI copilot for the browser |
| Sider | Freemium | Browser Extensions & Copilots | ChatGPT/Claude/Gemini in a browser sidebar |
| Brave Leo | Freemium | Browser Extensions & Copilots | Built directly into the Brave browser sidebar — no separate site, no account, no signup required for free tier |
| Dia | Freemium | Browser Extensions & Copilots | AI-native Chromium browser (from the makers of Arc) with AI chat built into every tab, not bolted on as a sidebar |
| Harpa AI | Freemium | Browser Extensions & Copilots | AI web automation and monitoring |