Merlin AI vs Monica

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors.

The short answer

Free plan: Both have one
Public API: Monica has one; not confirmed by us for Merlin AI
Best fit: Merlin AI: People who compare answers across frontier models before trusting one · Monica: People who compare answers across GPT, Claude and Gemini without paying three subscriptions
Platforms: Merlin AI: Web, Chrome extension, iOS, Android · Monica: Web, macOS, Windows, iOS, Android, Chrome extension
Trust score: About even — Merlin AI 86, Monica 86

From our own records as of each tool's last check. Anything we have not confirmed is left out rather than guessed. How we verify

Merlin AIBrowser sidebar running many chat models on any page

MonicaMulti-model AI assistant living in a browser sidebar

Side by side

Fact	Merlin AI	Monica
Category	Browser Extensions & Copilots	Browser Extensions & Copilots
Pricing model	Freemium	Freemium
Starts at	—	$9.90/mo
Public API	Not confirmed	Yes
Trust score	86 / 100	86 / 100
Platforms	Web, Chrome extension, iOS, Android	Web, macOS, Windows, iOS, Android, API, Chrome extension
Company	Foyer Tech Inc.	Butterfly Effect Pte. Ltd.
Launched	2022	2023
Last verified	Oct 27, 2026	Oct 15, 2026

What our research says

Merlin AI

Buy it if you genuinely rotate between GPT, Claude and Gemini and resent paying three subscriptions — the aggregation is the whole value. If you live inside one model, its native app is faster, cheaper and gets features first.

Pros

One subscription reaches a dozen-plus frontier and open models
Extension surfaces the assistant directly on Gmail, YouTube, Google and LinkedIn
Mobile apps sync history, so the browser session continues off desktop
Real free tier for evaluating before paying

Cons

'Unlimited' paid plans are governed by an opaque fair-use credit budget users hit without warning
Extension is desktop-Chromium only; mobile browsers get a reduced web app
Feature parity with each underlying model's own app is never complete
No developer API

Monica

Worth it if you want one subscription that reaches GPT, Claude and Gemini from wherever you already are; pointless if you live inside a single vendor's app and are happy there. The value is the sidebar and the model switching, not the intelligence, which is all rented.

Pros

Genuinely wide model roster, including image and video models, under one credit pool
Extension plus desktop plus iOS/Android means the same history follows you across devices
Separate prepaid developer API at platform.monica.im if you want the same aggregation in code

Cons

Prices are only visible after loading the pricing app, and the tier names have already shifted once (Unlimited became Max)
Advanced credits reset monthly, so heavy image or video use burns a Pro plan fast
You are a reseller's customer — outages, rate limits and model deprecations arrive second-hand
monica.cn is a separate China-market build run by a different legal entity, which confuses support and privacy expectations

Which one fits

Choose Merlin AI if you need

People who compare answers across frontier models before trusting one
Heavy in-browser workflows: summarising videos, articles and inbox threads in place
Users who want one bill instead of separate OpenAI, Anthropic and Google subscriptions

Choose Monica if you need

People who compare answers across GPT, Claude and Gemini without paying three subscriptions
Reading and summarising foreign-language pages and PDFs in-place while browsing
Light users who want AI attached to the browser rather than in another tab