Monica

Butterfly Effect

An all-in-one AI assistant extension and app that puts chat, page and video summaries, writing help, translation and image tools one keystroke away on any site.

Product preview

Overview

Monica bets that most people do not want another app to open — they want AI exactly where they already are. Its browser extension sits beside every page and PDF: select text to rewrite or translate, hit a shortcut to summarize a YouTube video, or open the sidebar to chat with the page itself. The same account follows you across web, desktop and mobile.

Under the hood it routes to frontier models from OpenAI, Anthropic, Google and others, so quality tracks the best available models rather than one vendor. The free tier is generous enough to evaluate properly, and the paid plan removes caps and unlocks stronger models. For students, marketers and analysts who live in the browser, it replaces half a dozen single-purpose tools.

Pros / Cons

Pros

AI available contextually on every page
Frontier models from multiple vendors in one plan
Strong summarization for articles and videos
Truly cross-platform with one subscription

Cons

Extension needs broad page permissions — a privacy tradeoff
Occasional feature sprawl makes the UI feel crowded
Best features gated behind the paid tier

Who it's for

Summarizing long articles, PDFs and YouTube videos

Rewriting and translating text in place while browsing

Drafting replies in webmail and social tools

A single AI subscription across work devices

Bottom line

The most complete browser-first AI assistant for people who want one tool instead of six.

Key Features

Assistant on every page

Page & YouTube summaries

Multi-model chat

Writing & translation tools

Cross-device sync

Compare Monica with alternatives

Monica vs ChatGPT Monica vs Claude Monica vs Gemini 4 products · Conversational AI

Frequently asked questions

What is Monica?

Monica is a Conversational AI tool developed by Butterfly Effect. The company was founded in 2023 and is headquartered in Singapore. An all-in-one AI assistant extension and app that puts chat, page and video summaries, writing help, translation and image tools one keystroke away on any site.