Gemini 4 Argon vs Opus 5.5: prices, limits and benchmarks compared

Gemini 4 Argon vs Opus 5.5 comes down to price, benchmarks and how much of each you can verify. Google released Gemini 4 Argon on October 13, 2026. Anthropic released Claude Opus 5.5 on September 22. This comparison is based on the products' docs and published results, read on October 27, 2026. We did not run either model ourselves.

Short version: until November 30, Gemini 4 Argon costs half as much as Opus 5.5 per token. After that, Google's listed price matches Opus 5.5's. On independent numbers, the one comparison we could read puts Opus 5.5 ahead in six of six domains.

Gemini 4 Argon vs Opus 5.5 at a glance

Sources: Google's announcement, Anthropic's Opus 5.5 model page and the Claude pricing page, all read on October 27, 2026. Prices change, so check the pages before you commit.

Price: half now, equal later

Google lists $2 per million input tokens and $10 per million output tokens for Gemini 4 Argon, and says that is an introductory rate that ends on November 30, 2026. After that the public model costs $4 and $20. Opus 5.5 is $4 and $20 today.

So the price gap is a six-week promotion, not a lasting difference. If you are comparing for a long project, compare at $4 and $20 on both sides.

Opus 5.5 also has a fast mode, up to 2.5 times faster at $8 input and $40 output per million tokens, according to Anthropic. Google's announcement does not describe an equivalent.

Context and limits

Both land at about one million tokens, but they describe it differently. Google says Gemini 4 Argon has a 1M unified input-output limit through the API, and does not say how that is split. Anthropic documents a 1M-token context window with up to 128K output tokens for Opus 5.5, and up to 300K on the Batch API with a beta header.

Neither company published rate limits for the API in the pages we read. Consumer limits differ in kind. Claude resets usage on a rolling five-hour window with weekly caps on paid plans, and Claude Pro is $20 a month ($17 on annual billing), according to its pricing page. We did not read the Gemini app plan limits for this article.

Features each company highlights

Google pitches Gemini 4 Argon at long-running agentic coding, multimodal document understanding and 3D and visual coding. It also describes a multi-layer safety stack and prompt-injection defenses. Anthropic pitches Opus 5.5 at long-running agentic coding and knowledge work, with adaptive thinking that cannot be turned off, forced tool use not supported and a 40% lower cost than Opus 5 on typical workloads, by Anthropic's account.

Benchmarks: what is independent and what is not

This is where the comparison gets thin. Most numbers come from the companies.

Independent results

• Artificial Analysis, read October 27, 2026: its capability comparison table shows Opus 5.5 at max effort ranked first in all six domains. Gemini 4 Argon at high effort ranks between third and ninth. The settings differ, so this is not a like-for-like test.

• The page we could read was truncated, and we did not see an overall Intelligence Index score for either model, nor speed or price figures.
• Epoch AI, read October 27: its benchmarks page says Opus 5.5 took the top spot on the Epoch Capabilities Index with 167 on October 1. The same page also shows 169 without a date. Gemini 4 Argon does not appear.
• SWE-bench, read October 27: neither model appeared in the part of the page we could read.

Company claims

• Google says Gemini 4 Argon ranks first on the Vals Index and scores 87% on the ERQA embodied reasoning benchmark, which it says beats other frontier models. The announcement gives no Vals score. The Gamow Labs results (57% on RareBench, 52.2% on LabBench) come from private evaluations.
• Anthropic reports Opus 5.5 at 66.4% on Terminal-Bench 4.0, with a standard error of 2.6 points, and 57.8% on CursorBench 4.0. Gemini 4 Argon is not in Anthropic's table, which was published three weeks before Google's release.

We found no benchmark where both companies report a score for both models, so there is no clean head-to-head from the labs.

Gemini 4 vs GPT-6

Google's announcement and Anthropic's pages do not compare Gemini 4 Argon with GPT-6 directly. The Artificial Analysis table, read October 27, lists GPT-6 Astra at max effort. It scores below Opus 5.5 in all six domains. Against Gemini 4 Argon it is ahead in finance (55 against 54), strategy (57 against 56) and healthcare (53 against 48), level in engineering (55) and economics (60), and behind in legal (59 against 60). That is one table on one date, and the effort settings differ.

Anthropic's own table puts GPT-6 Astra at 57.9% on Terminal-Bench 4.0 against Opus 5.5's 66.4%. We did not read OpenAI's pages for this comparison.

What we don't know yet

• Gemini 4 Argon's knowledge cutoff, rate limits, maximum output and batch pricing are not in the announcement.
• No independent score exists in what we read for Gemini 4 Argon on coding benchmarks such as SWE-bench or Terminal-Bench.
• Whether Google extends the introductory price past November 30 has not been announced.

Check the Artificial Analysis and Epoch pages again after November 30, when the Gemini price changes and more independent runs are likely to be in.