Head-to-head selection guide

Gemini 4 Argon vs Claude Opus 5.5

Gemini 4 Argon vs Claude Opus 5.5: official per-token prices (Argon is about half of Opus), ten benchmarks from Google's model card, 1M context and multimodal differences, and which to pick for coding agents, long documents and video. Prices on this page come live from the CallAI gateway.

Google

Gemini 4 Argon

gemini-4-argon
CallAI input:$2.20 / 1M
CallAI output:$11.00 / 1M
Official input:$2.00 / 1M
Official output:$10.00 / 1M
API model name:gemini-4-argon
Cache read / 1M:$0.1 / 1M
Context window:1M
Anthropic

Claude Opus 5.5

claude-opus-5.5
CallAI input:$4.40 / 1M
CallAI output:$22.00 / 1M
Official input:$4.00 / 1M
Official output:$20.00 / 1M
API model name:claude-opus-5.5
Cache read / 1M:$0.2 / 1M
Context window:1M
Verdict & selection advice

For coding, terminal agents and multi-step changes in large repos, pick Claude Opus 5.5 — it leads Terminal-bench 4.0 and FrontierSWE v2. For long documents and video at hundreds of thousands to a million tokens, or finance and legal knowledge-work agents, pick Gemini 4 Argon — it scores higher there at half the price. Both run on one CallAI key, so you can route per task.

Benchmarks from Google's model card (vendor-reported)

BenchmarkGemini 4 ArgonClaude Opus 5.5WinnerNotes
DeepSWE v1.177.9%74.2%Gemini 4 ArgonReal-codebase engineering tasks
FrontierSWE v255.0%62.3%Claude Opus 5.5Hard software engineering
Terminal-bench 4.057.4%66.4%Claude Opus 5.5Terminal agent tasks; Anthropic's own table also reports 66.4%
AutomationBench51.3%42.5%Gemini 4 ArgonKnowledge-work automation
Vals Finance Agent v265.4%58.6%Gemini 4 ArgonFinance analyst agent
PostTrainBench45.3%49.3%Claude Opus 5.5ML engineering
Terminal-Bench Science 0.157.6%63.3%Claude Opus 5.5Scientific terminal tasks
GraphWalks 256K–1M (BFS F1)84.2%66.8%Gemini 4 ArgonVery long context reasoning — the widest gap in the table
LVBench91.7%83.7%Gemini 4 ArgonLong video understanding
Agent's Last Exam39.5%38.2%TieComputer-use agents, within 2 points

Gemini 4 Argon strengths & weaknesses

Strengths:
  • About half the list price of Opus 5.5 ($2 / $10 vs $4 / $20 per 1M tokens)
  • Leads very long context reasoning: GraphWalks 256K–1M 84.2% vs 66.8%
  • Accepts text, image, video, audio and PDF; LVBench long-video score 91.7%
  • Stronger knowledge-work agents: AutomationBench 51.3%, Vals Finance Agent v2 65.4%
Weaknesses:
  • Text output only — no image or audio generation
  • Implicit caching only; explicit caching is not supported
  • Behind on terminal agents and hard engineering: Terminal-bench 4.0 57.4%, FrontierSWE v2 55.0%
  • Computer use is still in preview

Claude Opus 5.5 strengths & weaknesses

Strengths:
  • Terminal-bench 4.0 at 66.4%, the top score in Google's table
  • Leads Argon on FrontierSWE v2 (62.3%) and PostTrainBench (49.3%)
  • Anthropic positions it for multi-step changes in large codebases and long-horizon agents
  • Cache reads at $0.20 / 1M make repeated long system prompts much cheaper
Weaknesses:
  • Twice the list price of Argon
  • Clearly behind on 1M-scale context reasoning (GraphWalks 256K–1M 66.8%)
  • Lower scores on knowledge-work automation and finance agents

Scenario recommendations

ScenarioPickWhy
Terminal agents and multi-file refactors in Claude Code / CursorClaude Opus 5.59 points higher on Terminal-bench 4.0 and 7.3 points higher on FrontierSWE v2.
Whole contracts, filings or codebases in one contextGemini 4 ArgonLeads 256K–1M context reasoning by more than 17 points at half the price.
Video and audio analysisGemini 4 ArgonNative video and audio input; LVBench 91.7% vs 83.7%.
Budget-sensitive batch workGemini 4 ArgonThe same token volume costs about half at list prices.

Python dual-model gateway sample

OpenAI-compatible

One Base URL and API key — switch models with the model parameter only:

import os
from openai import OpenAI

# One CallAI key — route freely between Gemini 4 Argon and Claude Opus 5.5
client = OpenAI(
    api_key="sk-live-your-callai-key",
    base_url="https://api.callaiapi.com/v1"
)

def query_model(model_id: str, prompt: str):
    response = client.chat.completions.create(
        model=model_id,
        messages=[{"role": "user", "content": prompt}],
        stream=True
    )
    for chunk in response:
        print(chunk.choices[0].delta.content or "", end="", flush=True)
    print("\n" + "="*40 + "\n")

# Model 1: Gemini 4 Argon
print(">>> Output from: Gemini 4 Argon")
query_model("gemini-4-argon", "Briefly analyze the trade-offs of this architecture")

# Model 2: Claude Opus 5.5
print(">>> Output from: Claude Opus 5.5")
query_model("claude-opus-5.5", "Briefly analyze the trade-offs of this architecture")

FAQ

How much do Gemini 4 Argon and Claude Opus 5.5 cost per token?

List prices as of 2026-10-22: Gemini 4 Argon is $2 input and $10 output per 1M tokens; Claude Opus 5.5 is $4 input and $20 output per 1M tokens. The cards at the top of this page show the current CallAI price, updated from upstream automatically.

Who ran these benchmarks?

The numbers come from Google DeepMind's Gemini 4 Argon model card (2026-10-13) and are vendor-reported, including the Opus 5.5 column. Terminal-bench 4.0 at 66.4% matches Anthropic's own launch table. No independent verification yet.

How do I call Gemini 4 Argon and Claude Opus 5.5 through one API?

Create a key in the CallAI console, set the OpenAI SDK base_url to https://api.callaiapi.com/v1 and use the model name shown on the cards. Pay as you go from $1, with crypto and card payments; balance never expires.

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