The short answer: Opus for agents, Argon for long context and price now
Choose Claude Opus 5.5 for coding agents and computer use, where Google DeepMind's table lists it ahead. Choose Gemini 4 Argon for very long-context reasoning or if you want the introductory $2 and $10 price before it rises to match Opus on December 1.
Scope and evidence
Task: choosing a frontier model for coding, agents and long documents. Argon facts come from the Gemini API documentation and pricing; benchmarks from the comparison table on Google DeepMind's Gemini page, where rival scores are mostly provider-reported; Opus facts from Anthropic's overview and pricing. Pages read on October 30 and 31, 2026.
AppFor.ai did not run either model for this page.
Compare the same criteria
Each line pairs Google's figure for Argon with the Opus figure from the same table or Anthropic's docs.
- API price per million tokens. Argon: $2 input, $10 output until November 30, 2026, then $4 and $20. Opus 5.5: $4 and $20. What this means: Argon is half price for one more month.
- Context. Argon: 1,048,576 tokens. Opus: 1M context, 128K output. What this means: equal in practice.
- Artificial Analysis Intelligence Index, per Google's table. Argon: 50. Opus: 58. What this means: Opus leads overall.
- FrontierSWE 2 and Terminal-Bench 4.0. Argon: 55.0% and 57.1%. Opus: 62.3% and 59.6%. What this means: Opus ahead on coding, by more on FrontierSWE.
- OSWorld computer use. Argon: 74.7%. Opus: 87.2%. What this means: a clear Opus lead for agents that operate apps.
- GraphWalks long-context reasoning. Argon: 84.2%. Opus: 66.8%. What this means: Argon's strongest advantage.
Which fits your real work?
A developer running a coding agent on a large repository. Opus 5.5 fits on the published coding scores.
An analyst asking questions across a long set of linked records. Argon fits on GraphWalks and price.
Someone who already pays for Google AI Pro and drafts in the Gemini app. Argon comes with that plan, while Opus needs a Claude subscription.
Cost of getting the work done
API: 2 million input and 200,000 output tokens cost $6 on Argon until November 30 and $12 after; $12 on Opus 5.5 before Anthropic's 50% Batch discount.
Apps: Argon comes with Google AI Pro and Ultra; Opus 5.5 with Claude Pro at $20 a month billed monthly.
Try both on the same small task
Suggested check: run one long-context task and one coding task on both.
- Every cited section exists and says what the model claims.
- The test runs.
- Compare tokens and cost per task.
- Repeat three times per model.
Decision checklist
Use the lines that match your situation. Details are in our profiles of both models.
- If agents operate apps or terminals, choose Opus 5.5.
- If long-context reasoning dominates, try Argon first.
- If cost matters this month, Argon's introductory price halves it.
- If you already pay for Google AI Pro, start with Argon.
- Re-check prices after November 30, 2026.
Go to the source
Sources & further reading
Based on the official documentation below. Features and access can change; check the provider before making a decision.
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