Google Gemini 4 Argon vs Claude Opus 5.5

Both are leading frontier models as of October 2026. Argon shines at very long outputs, long video, and Google’s ecosystem. Opus 5.5 shines through Claude’s tools for coding and work, such as Claude Code, Cowork, and the Office add-ins. The right pick depends on your work, not on any single benchmark.

Test both on your real tasks. The right model is whichever one does your work best.

Gemini 4 Argon

Announced September 30, 2026, and released in phases. Available in the Gemini app for Google AI Pro and Ultra since October 13

Claude Opus 5.5

Released September 22, 2026. Available in Claude apps on paid plans, in Claude Code, and through the API

Gemini 4 Argon

$2 input and $10 output at launch, rising later to $4 and $20

Claude Opus 5.5

$4 for input and $20 for output

Both give steep discounts on cached input. Check current prices before you set a budget.

Gemini 4 Argon

Roughly 1 million tokens of context, and long outputs of up to 1 million tokens

Claude Opus 5.5

1 million tokens of context, and up to 128,000 output tokens

Gemini 4 Argon

Thinking levels LOW, MEDIUM, and HIGH, with MEDIUM set by default

Claude Opus 5.5

Effort levels from low to max, with medium set by default. Thinking stays on at all times

Gemini 4 Argon

Google reports a record 77.9% on DeepSWE v1.1, plus agentic coding in Google Antigravity

Claude Opus 5.5

Runs Claude Code, with subagents, skills, plugins, mods, and deep tool support

Most coding benchmarks are self-reported. Run both models on your own repository.

Gemini 4 Argon

Strong at understanding long video and analyzing charts, with Workspace integration

Claude Opus 5.5

Strong at long documents, with Claude for Excel, PowerPoint, and Word, plus Claude Docs and Slides

Gemini 4 Argon

Tasks mode in the Gemini app, plus connections to more than 40 apps

Claude Opus 5.5

Claude Cowork, connectors, Projects, and agents in Claude Code

• Google calls Argon its most resistant model yet against indirect prompt injection
• Claude Opus 5.5 uses safety classifiers that may decline some requests
• Both still need human review for high-stakes work

Your work lives in Google Workspace

Gemini 4 Argon

Your work lives in Microsoft Office or Claude Code

Claude Opus 5.5

You need very large single outputs

Gemini 4 Argon

You want the cheapest API price at launch

Gemini 4 Argon, for as long as its introductory price lasts

You want mature tools for coding agents

Claude Opus 5.5

• Choose five real tasks from your work
• Give both models identical input and instructions
• Match their reasoning settings as closely as you can
• Score accuracy, quality, speed, and cost
• Test again after every major update