Claude Opus 5.5 vs Gemini 4 Argon

Quick Answer

Claude Opus 5.5 is the stronger model on the independent benchmark we track, scoring 58 on Artificial Analysis’s Intelligence Index against 53 for Gemini 4 Argon. Argon is the cheaper model by a wide margin, both per token and per task. Opus also writes far more tokens on hard problems, which makes it slower to finish and more expensive than its list price suggests.

If quality on the hardest work is what matters, Opus 5.5 has the edge on available evidence. If cost per task, very long outputs, or Google’s ecosystem matter more, Argon is the practical choice.

At a Glance

What Each Model Is For

Claude Opus 5.5 is Anthropic’s model for long-running agentic coding and knowledge work, a step below its Fable 5.1 flagship in price and capability. It runs Claude Code, powers Claude Duet, and is the model many developers reach for on hard repository work.

Gemini 4 Argon is Google’s frontier model for long, multi-step work across software engineering, legal and finance work, and cybersecurity defense, available in the Gemini app, AI Mode, the paid API, AI Studio, and Antigravity.

Coding and Agent Work

Both are built for multi-step agentic work. On independent evidence, Opus 5.5 scores higher on the overall index. Google’s tables claim Argon wins more individual benchmarks than Opus 5.5 or GPT-6 Astra, but independent coverage notes Argon trails on some agentic coding suites. For coding specifically, the surrounding tool matters too: Opus inside Claude Code with Code Review is a mature workflow, while Argon inside Antigravity is newer.

Documents and Long Context

Both accept about 1M tokens of input, enough for large codebases or document sets. The difference is on output: Opus caps at 128K output tokens, while Google says Argon can produce up to 1M. If you need a very long report, translation, or code generation in one pass, that matters. For reading and analysis, both are capable, and Claude’s Docs, Slides, and Dashboards features make it a convenient place to turn analysis into a deliverable.

The Verbosity Factor

Opus 5.5’s list price is double Argon’s launch price, but its real cost gap is larger. In Artificial Analysis’s run it produced about 260M output tokens against Argon’s 110M, and cost about three times as much per task ($5.98 versus $1.99). Extended reasoning helps on hard problems and is wasted on easy ones. Anthropic’s effort controls and Google’s thinking settings both let you dial this down, and routing easy work to cheaper models such as Sonnet 5.5 or Gemini 3.8 Flash is usually the bigger saving. See cost per completed task and effort routing.

Safety and Availability

Both shipped with staged access: Argon first to vetted cyber defenders, and both companies participate in US government pre-release testing. Opus 5.5 is broadly available on paid Claude plans and the API. Argon in the consumer app requires Google AI Pro or Ultra.

Choose Claude Opus 5.5 If

Quality on hard reasoning and coding is worth paying for, you use Claude Code or Claude’s document and dashboard tools, or your tests show it gets accepted results with fewer retries.

Choose Gemini 4 Argon If

You want near-frontier quality at a much lower cost per task, you need very long outputs, you are building high-volume agents, or you work in Google’s ecosystem.

When Neither Is Ideal

For everyday tasks, both are overkill; Claude Sonnet 5.5 and Gemini 3.8 Flash are cheaper and faster. For open weights you can self-host, see Muse Spark Open vs Mistral Large 4.

Final Recommendation

Opus 5.5 is the higher-scoring model; Argon is the better-value one. Many teams will use both: Argon or a fast model for the bulk of work, and Opus for the steps where its extra quality changes the outcome. That is model escalation in practice.

Related Comparisons

• GPT-6 Astra vs Gemini 4 Argon
• GPT-6.1 Sol vs Claude Opus 5.5
• Gemini 4 Argon vs GPT-6.1 Sol
• Muse Wonder vs Claude Opus 5.5
• Claude vs Gemini