Pick Monica if…
you want frontier models at the lowest monthly price, or need a free tier you can use daily.
These two sell the same idea: several frontier chat models plus page summaries and writing help in the browser, also on desktop and mobile. Where they part ways is the plan structure. Monica counts queries, splitting basic and advanced models, and meters agent, image and video work in separate Advanced Credits. Merlin has one main Pro plan with unlimited basic models, 70+ AI tools and higher-end models, under fair-use limits.
Pick Monica (Pro at $9.90/mo) for a cheaper way into GPT-6.1 Sol, Claude Sonnet 5.5 and Gemini 4 Argon, with a free tier of 40 queries a day. Pick Merlin AI (Pro at $29/mo) if you want Claude Opus 5.5, YouTube summaries and 70+ tools in a Chrome sidebar, with unlimited Basic models.
| App | Free tier | Paid from | Top plan | Best for |
|---|---|---|---|---|
| Monica | Yes | $9.90/mo | $99.90/mo | Users who want several frontier chat models plus summarizing, translation and writing help inside every web page for one low price |
| Merlin AI | Yes | $29/mo | $29/mo | Browser-heavy users who want frontier models, page summaries and YouTube summaries in a Chrome sidebar |
Monthly prices in US dollars before tax, from each vendor's official pricing (US list price; weekly-billed plans converted to a monthly figure). Updated November 2, 2026
| Monica | Merlin AI | |
|---|---|---|
| Free tier | 40 basic-model queries/day, limited agent and image trials | Limited Basic and Plus-level models, basic image generation |
| Entry paid plan | Pro: 5,000 basic + 200 advanced queries/mo | Pro: unlimited Basic models, 50x usage on Plus-level models |
| Top models | GPT-6.1 Sol, Claude Sonnet 5.5, Gemini 4 Argon | GPT-6.1 Sol, Claude Opus 5.5 |
| Agent, image, video | Separate Advanced Credits (1,500/mo on Pro) | Advanced image & video generation on Pro |
| Fair-use catch | Max/Ultra "unlimited" drops to 100/day past the quota | Pro has fair-use limits; top-up credits beyond them |
| Devices & teams | Login devices rise by tier (3/5/10) | Teams plan per seat, 2-seat minimum, SOC 2 |
you want frontier models at the lowest monthly price, or need a free tier you can use daily.
you live in Chrome, summarise a lot of YouTube and web pages, and want Opus-class access with a team option.
Yes, at entry: Monica Pro is $9.90/mo against $29/mo for Merlin Pro. Monica Max ($24.90/mo), with unlimited queries under fair use, is still below Merlin Pro.
Neither fully. Monica Max and Ultra fall to 100 queries a day after the monthly fair-use quota. Merlin Pro has fair-use limits too, and going past them needs paid top-up credits.
Both do. Monica Free gives 40 basic-model queries a day; Merlin Free gives limited access to Basic and Plus-level models and its 70+ tools.
How we choose: prices come from each vendor's official pricing page and are re-checked every week. We take no affiliate fees, so rankings aren't for sale.