HARPA 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 HARPA AI
Best fit: HARPA AI: Sales and research work that repeats the same extract-then-summarise loop across many pages · Monica: People who compare answers across GPT, Claude and Gemini without paying three subscriptions
Platforms: HARPA AI: Web, Chrome extension · Monica: Web, macOS, Windows, iOS, Android, Chrome extension
Trust score: About even — HARPA AI 85, 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

HARPA AIBrowser extension pairing chat models with web page automation

MonicaMulti-model AI assistant living in a browser sidebar

Side by side

Fact	HARPA 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	85 / 100	86 / 100
Platforms	Web, Chrome extension	Web, macOS, Windows, iOS, Android, API, Chrome extension
Company	HARPA AI TECHNOLOGIES LLC	Butterfly Effect Pte. Ltd.
Launched	—	2023
Last verified	Oct 15, 2026	Oct 15, 2026

What our research says

HARPA AI

The strongest option if you want one extension that both discusses a page and acts on it, and it earns its price only if you actually build repeatable web workflows. For plain summaries and a chat sidebar, cheaper single-purpose extensions do the same job.

Pros

Commands run against the live DOM, so they work on pages behind a login
Bring-your-own-key and web-session modes keep running costs down
Registered EU entity with GDPR and ISO 27001 claims, unusual for an extension
Lifetime licence exists for people who refuse subscriptions

Cons

The command builder has a genuine learning curve
Token metering makes monthly spend hard to forecast
No developer API of its own, despite the automation positioning
Automations break when target sites change their markup

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 HARPA AI if you need

Sales and research work that repeats the same extract-then-summarise loop across many pages
People who prefer bringing their own model API keys over another per-seat AI subscription
Watching pages for price or stock changes and firing alerts

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