Google Gemini 4 Argon review.

Google's best model is half price until November 30. Then it costs exactly what Claude does

Here's the number most launch coverage buried. Through November 30, 2026, Gemini 4 Argon costs developers US$2 per million input tokens and US$10 per million output tokens on Google's official pricing page. On December 1 that doubles to $4 and $20. That's exactly what Anthropic charges for Claude Opus 5.5, and well under the $10 and $50 OpenAI lists for GPT-6 Astra.

So the bargain everyone is talking about has a seven-week shelf life. After that, Argon has to win on quality and on how many tokens it burns, not on a promo.

Argon is Google's new frontier AI model, the top of the Gemini line. Google announced it on September 30, gave it first to cybersecurity teams in its Fairwind program, then opened it on October 13 to developers, businesses and Google AI Pro and Ultra subscribers in the Gemini app and AI Mode in Search. In Canada that means $26.99 CAD a month for Pro or $139.99 CAD and up for Ultra on Google's Canadian plans page.

This review answers one question: is Argon worth paying for, as a subscriber or a developer, now that the hype has met the price list?

What's actually new over Gemini 3.1 Pro, and why there's no 3.5 Pro

Argon replaces Gemini 3.1 Pro as Google's top model, and it skips a step. Gemini 3.5 Pro was promised at Google I/O in May and never shipped; 9to5Google described it as cancelled, and R&D World reported Bloomberg's account of delays tied to coding shortfalls. Google DeepMind's model card says Argon is a new sparse mixture-of-experts model, not a fine-tune of an older one.

The changes that matter: a context window of about 1 million tokens shared between what you send and what it writes back, and long replies that can run far past the 64,000-token output cap of earlier Gemini models. Artificial Analysis scores it 23 points above Gemini 3.1 Pro Preview on its Intelligence Index, according to R&D World. In the app, Google says it hedges less, repeats itself less and gives progress updates on long jobs. It also arrived with a new tasks mode that keeps working after you close the tab.

Who shouldn't bother? If you're on the free Gemini plan, there's nothing to upgrade to: Argon isn't on the free tier. If you mostly use Gemini for quick questions, email drafts and recipes, Gemini 3.8 Flash already handles that and won't chew through your limits.

It tops the professional-work leaderboards, but the coding crown isn't Google's

Start with the independent numbers, because launch charts are marketing. Vals AI, which tests models on finance, legal, tax and coding work, ranks Argon first on its Vals Index at 68.9%. Claude Opus 5.5 scored 67.0% and Claude Fable 5.1 65.8%. Argon also ranks first on Vals' Finance Agent test at 65.4% and fourth on its Legal Research Bench. The Batch reported Argon at the top of Arena's crowd-voted text leaderboard at launch, narrowly ahead of Opus 5.5.

Artificial Analysis is cooler on it. Its Intelligence Index gives Argon 53, level with GPT-6 Astra and Fable 5.1 but behind Opus 5.5 at 58, according to R&D World. On Arena's agent leaderboard it sat eighth overall. Strong, clearly frontier, not a runaway winner.

Coding is the weak spot, and Google's own model card shows it. Argon leads DeepSWE v1.1 at 77.9% and Vibe Code Bench at 91.9%, but it trails GPT-6 Astra on FrontierSWE v2 (55.0% to 65.5%) and Claude Opus 5.5 on Terminal-bench 4.0 (57.4% to 66.4%). Owners on r/Bard and r/GeminiAI land in the same place: several call it excellent for research, writing and math, and a fair few say they'd still pick Claude or OpenAI's Codex for serious coding.

The takeaway: if your work is reading, reasoning and writing, Argon is at or near the top. If it's agents rewriting large codebases, it's competitive but not the first pick.

The hallucination number that matters for real work

The most useful number for a lot of people isn't a coding score. Artificial Analysis runs a knowledge test called AA-Omniscience that punishes wrong answers but not 'I don't know'. The Batch reports Argon on high reasoning hallucinated 15% of the time there, the lowest among models scoring 45 or more on the Intelligence Index. GPT-6 Astra on its maximum setting came in at 51%.

In plain terms, Argon is more willing to say it doesn't know instead of making something up. The Batch called it the frontier model most likely to admit uncertainty, which is exactly what you want when checking a contract clause, a tax rule or a medical-sounding claim before acting on it.

Two caveats. That test runs without web search, and models with search tools behave differently. And early owner reports are mixed: a few posts in r/GeminiAI complain of hallucinations and loose instruction-following in the first days, while others praise its research answers. Google's model card still lists hallucinations, and occasional slowness or timeouts, as known limits. Lower doesn't mean zero, so keep checking anything that costs money if it's wrong.

The token bill: why a low price per token can still cost you more

Price per token is only half the bill. The other half is how many tokens the model spends thinking before it answers, and Google bills that thinking as output. Artificial Analysis found Argon used about 62,000 output tokens per task on its index, against about 27,000 for GPT-6 Astra, R&D World reported. At the intro price that still worked out cheaper per task, $1.99 against $3.26. At the December price Argon's cost doubles to $3.98, and Astra wins.

Vals AI's numbers, run at the full $4 and $20 price, are friendlier. Argon cost $15.68 per Vals Index run, compared with $32.14 for Claude Opus 5.5 and $28.71 for Fable 5.1. So it depends on the job: on long professional tasks it can still be the cheaper frontier model, while on lots of short tasks it can run up a bigger bill than its sticker suggests.

Where Argon clearly saves money is very long prompts. Google lists no long-context tier for Argon, so feeding it a 700-page contract bundle costs the same per token as a one-line question. Gemini 3.1 Pro charges $4 and $18 once a prompt passes 200,000 tokens, and OpenAI doubles Astra's input price past 272,000. Batch and Flex requests run at half price if you can wait. One catch for developers: Argon only supports implicit caching, so the old explicit-cache setups have to go.

What $26.99 a month gets you in Canada, and what it doesn't

Google's Canadian plans page lists three paid tiers: AI Plus at $6.99 CAD a month, AI Pro at $26.99 CAD and AI Ultra from $139.99 CAD, with a 20x Ultra plan at $279.99. Argon is tagged as included with Pro and Ultra. Pro gets it in the Gemini app and AI Mode in Search; Ultra adds 'higher' access plus Argon in Google Antigravity, Google's coding-agent tool, and in AI Studio.

That split annoys Pro owners. Threads on r/singularity, r/Bard and r/GeminiAI from launch day are full of Pro subscribers finding Argon in the app but not in AI Studio or Antigravity. Google's API pricing page confirms it: Argon isn't on the free tier or the Google AI Pro plan in AI Studio. Pay-as-you-go API access with billing turned on is the way around it.

The bigger complaint is limits. Several Pro owners report a single Argon prompt using somewhere between 1% and 10% of their five-hour usage window, with roughly 5% per question a common figure. Google only describes Pro as '4x' a free account and Ultra as 5x or 20x Pro, and its help pages say limits can change without notice.

Is it available here? Google's Canadian pages sell Pro and Ultra with Argon at CAD prices, Canada is on Google's list of countries for AI Pro and Ultra, and the tasks help page excludes only the EEA, Nigeria, Switzerland and the UK. Google still says 'selected countries' for Argon without publishing a separate list, and the rollout to Pro accounts was staggered on launch day.

How it stacks up against Claude Opus 5.5, GPT-6 Astra and Google's own cheaper models

On the API, prices are in US dollars and none of these companies publishes CAD rates. Claude Opus 5.5 is $4 and $20 per million tokens, the same as Argon after November 30. It leads Artificial Analysis's index and Terminal-bench, so it's the safer pick for agent-heavy coding. Anthropic's Claude Pro plan is US$20 a month and includes Opus.

GPT-6 Astra costs $10 and $50, more than double, and rises to $20 and $75 past 272,000 input tokens. It matched Argon on Artificial Analysis's index, beat it on FrontierSWE and OSWorld computer-use tests, and used fewer tokens per task. It's worth the premium only if those specific strengths are your job. OpenAI's GPT-6.1 Sol at $2 and $10 is the cheaper alternative from that side.

Inside Google's lineup, Gemini 3.8 Flash is $0.75 and $3.75 until December 31 and handles everyday work for far less. Gemini 3.1 Pro is still around at $2 and $12 for shorter prompts. If you mainly want AI for images and video rather than text, our OpenArt and Higgsfield reviews cover tools built for that instead.

Living with it: limits, knowledge cutoff and the fine print for Canadian businesses

For subscribers, the ongoing cost is simple: the monthly fee, billed in CAD, and limits you can't see in advance. Expect to save Argon for the hard questions and leave quick chats to Flash. Several owners also noticed it was unsure about recent events until it searched the web. Google's model card puts its knowledge cutoff at March 2026, so turn on search for anything newer.

For developers, Google's Cloud guide lists breaking changes from Gemini 3.1 Pro. Temperature, top-p and top-k are ignored, the old thinking-budget setting returns an error, prefilled replies aren't allowed and explicit caching is gone. Long replies need a newer SDK and a continuation token. None of it is hard, but budget a day to migrate rather than swapping the model name and hoping.

Canadian businesses should note where the data goes. Google's Cloud guide lists global, US and EU endpoints for Argon and no Canadian region, which matters if your contracts or provincial rules require Canadian data residency. The Gemini API and AI Studio are available in Canada, though, and the model is offered through Gemini for business.

Buy it, skip it, or buy this instead

Buy into Argon if your work is research, long documents, finance, legal or academic writing, where its Vals results and low hallucination rate pay off. Developers with huge prompts should move now, while the intro price lasts, and keep it after December 1 if their tasks are long rather than chatty. If you already pay $26.99 for Google AI Pro, try it on your hardest question this week and see whether the limits fit your day.

Skip it, or at least skip Ultra, if you mainly want a coding agent. Claude Opus 5.5 costs the same per token and leads on the agent benchmarks that matter there. Skip it too if your daily AI use is light: Google AI Plus at $6.99 CAD a month, which includes Google's Flash models and Deep Research, covers most of that for about a quarter of the price.