Gemini 4 Argon vs Claude Opus 5.5: Benchmarks, Pricing, and Key Differences

Google's Gemini 4 Argon and Anthropic's Claude Opus 5.5 are two flagship AI models designed for advanced reasoning, coding, and complex business workflows.

Gemini 4 Argon stands out in knowledge work, long-context reasoning, and video understanding. Claude Opus 5.5 performs strongly in terminal-based coding and multi-step software engineering tasks.

While both models offer advanced capabilities, the best choice depends on your workload, integration needs, and budget.

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What Is Gemini 4 Argon?

Gemini 4 Argon is Google DeepMind's advanced reasoning model, made generally available in October 2026 through the Gemini API, Google Cloud, and the Gemini app.

It is designed for complex, multi-step tasks involving large documents, coding, finance, legal research, cybersecurity, and science.

Key strengths:

• Strong performance on knowledge-work benchmarks.

• A context window of up to 1 million tokens.

• Advanced long-document and video understanding.

• Flexible reasoning levels.

• Lower introductory API pricing through November 2026.

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What Is Claude Opus 5.5?

Claude Opus 5.5 is Anthropic's flagship model, released on September 22, 2026. It focuses on advanced reasoning, coding, and long-running software engineering tasks.

The model is particularly suited to complex codebase changes, terminal-based agent workflows, and tasks that require constraints to be maintained across multiple steps.

Key strengths:

• Strong terminal-based coding performance.

• Advanced codebase analysis and refactoring.

• Adaptive reasoning with configurable effort.

• Support across major cloud platforms.

• A maximum output limit of 128K tokens.

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Gemini 4 Argon vs Claude Opus 5.5: Key Differences

Feature	Gemini 4 Argon	Claude Opus 5.5
Developer	Google DeepMind	Anthropic
Release	October 2026	September 22, 2026
Context window	1,048,576 tokens	1 million tokens
Default maximum output	65,536 tokens	128K tokens
Extended output	Up to 1,048,576 tokens with long decode	128K tokens
Knowledge work	Stronger across Google's shared benchmark table	Competitive
Terminal-based coding	Strong	Stronger on key benchmarks
Long-context reasoning	Leads on the reported GraphWalks tests	Performance drops more at longer context lengths
Introductory API pricing	50% lower until November 30, 2026	Standard pricing
Best suited for	Research, long documents, finance, and legal workflows	Coding agents and complex software engineering

According to Google's published comparison, Gemini 4 Argon scores higher on 14 of the 18 shared benchmark rows. Claude Opus 5.5 leads on four, including several important terminal-based coding tests.

These results reflect Google's benchmark methodology, so they should be considered alongside each model's actual performance on your tasks.

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How the Models Compare Across Benchmarks

1. Agentic Coding

Claude Opus 5.5 performs better on several terminal-focused coding benchmarks, while Gemini 4 Argon performs strongly on long-horizon software engineering.

Benchmark	Gemini 4 Argon	Claude Opus 5.5
Terminal-bench 4.0	57.4%	66.4%
FrontierSWE v2	55.0%	62.3%
PostTrainBench	45.3%	49.3%
DeepSWE v1.1	77.9%	74.2%
Vibe Code Bench	91.9%	90.3%

Claude Opus 5.5 is the stronger option for terminal-based agents and multi-step coding tasks. Gemini 4 Argon remains competitive for large refactoring projects and extended software engineering workflows.

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2. Knowledge Work and Business Applications

Gemini 4 Argon leads across the knowledge-work benchmarks reported in Google's comparison, including finance, automation, and legal research.

Benchmark	Gemini 4 Argon	Claude Opus 5.5
Vals Index	68.9%	67.0%
AutomationBench	51.3%	42.5%
Vals Finance Agent v2	65.4%	58.6%
Harvey's Legal Agent Benchmark	19.6%	3.8%

For teams building financial research agents, legal assistants, and document-analysis systems, Gemini 4 Argon is a promising choice based on these results.

However, benchmark performance does not guarantee the same outcome across every business workflow. Testing both models against representative tasks remains important.

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3. Long Context and Multimodal Capabilities

Gemini 4 Argon has an advantage when working with extremely long inputs and video-related tasks.

Benchmark	Gemini 4 Argon	Claude Opus 5.5
GraphWalks, up to 128K tokens	99.7%	90.6%
GraphWalks, 256K–1M tokens	84.2%	66.8%
LVBench	91.7%	83.7%
Chartography	71.6%	66.3%

Argon's reported performance makes it suitable for analyzing large contracts, extensive research documents, and long video content.

Claude Opus 5.5 offers a larger default output limit, making it convenient for generating long responses without additional output configuration.

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4. Science, Security, and Computer Use

Both models demonstrate capabilities in scientific reasoning, cybersecurity, and computer-use tasks.

Benchmark	Gemini 4 Argon	Claude Opus 5.5
LABBench 2	88.8%	73.1%
RiemannBench	76.0%	69.6%
Terminal-Bench Science 0.1	57.6%	63.3%
CWE-bench v1	68.0%	67.0%
Agent's Last Exam	39.5%	38.2%

Gemini 4 Argon leads on the reported science and mathematics benchmarks, while Claude Opus 5.5 performs better on the terminal-based science task.

Their cybersecurity and computer-use scores are relatively close in this comparison.

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When Should You Choose Gemini 4 Argon?

Choose Gemini 4 Argon if:

• You work with long documents: Its large context window is useful for analyzing extensive contracts, reports, and research material.

• You build business research agents: Its reported knowledge-work performance makes it a strong candidate for legal and financial applications.

• You need video understanding: It performs well on the reported long-video benchmark.

• You want lower introductory costs: Its API pricing is half the standard rate of Opus 5.5 until November 30, 2026.

• Your organization uses Google's ecosystem: You can integrate it through supported Google AI and cloud services.

When Should You Choose Claude Opus 5.5?

Choose Claude Opus 5.5 if:

• You build coding agents: It leads on key terminal-based coding benchmarks.

• You handle complex codebases: It is designed for extensive code changes, migrations, and multi-step engineering work.

• You need consistent execution: It is a strong candidate for workflows where constraints must be maintained throughout a task.

• You use multiple cloud providers: It is available through Anthropic's platform and supported cloud integrations.

• You generate long outputs: Its 128K output limit is available without Argon's additional long-decode setup.

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How to Get Started With Both Models

Platform	Gemini 4 Argon	Claude Opus 5.5
Consumer applications	Gemini app	Claude apps
First-party API	Gemini API	Claude Platform
Cloud platforms	Google Cloud Vertex AI	Amazon Bedrock, Google Cloud Vertex AI, Azure AI Foundry
Coding tools	Google Antigravity and supported integrations	Claude Code, Cursor, GitHub Copilot
Third-party routing	OpenRouter	OpenRouter
API model ID	gemini-4-argon	claude-opus-5-5

For direct access, developers can use the respective first-party APIs. Third-party routing services may also allow teams to switch between models through a shared interface.

Before deployment, verify model availability, access requirements, and current pricing on the relevant provider's platform.

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Conclusion

Gemini 4 Argon and Claude Opus 5.5 serve different priorities. Argon is a compelling choice for knowledge work, long-context reasoning, and research-heavy business workflows. Opus 5.5 stands out for terminal-based coding and complex software engineering.

For businesses, the decision should come down to the work being performed, integration requirements, reliability, and total cost. Test both models on real tasks before committing to one for production.