API Free WeekHundreds of APIs are free to call this week.Browse free APIs

MODEL COMPARISON

Claude Opus 5.5 vs Gemini 4 Argon

Claude Opus 5.5 scores higher on the Artificial Analysis Intelligence Index (57.6 vs 52.6 for Gemini 4 Argon); Gemini 4 Argon costs less per task ($1.99 vs $5.98 for Claude Opus 5.5). Both run through one SandBase API key.

The two frontier flagships of October 2026, tested head to head on the same prompts.ONE API KEY · BOTH MODELS
  • IntelligenceClaude Opus 5.510% higher
  • Cost per taskGemini 4 Argon67% cheaper

Which one to pick

Each line is backed by a number in the table below.

  • The hardest reasoningClaude Opus 5.5

    Claude Opus 5.5 leads the Intelligence Index, 57.6 against 52.6.

  • High request volumeGemini 4 Argon

    Gemini 4 Argon finishes the same index for $1.99 instead of $5.98, so the gap compounds with every run.

Side by side

Prices are per 1M tokens on SandBase, after any public discount. Better value per row is marked.

MetricClaude Opus 5.5Gemini 4 Argon
Input / 1M tokens$3.80Better$4
Output / 1M tokens$19Better$20
Context window1M1M
Intelligence IndexAA57.6Better52.6
Cost per taskAA$5.98$1.99Better
Output speedAA95 tok/s—

Rows marked AA — Data: Artificial Analysis, snapshot 2026-10-14. Claude Opus 5.5 on AA ↗ Gemini 4 Argon on AA ↗ Full rankings: SandBase Lab leaderboards.

Switching between them

Same key, same endpoint, same request shape.

Call Claude Opus 5.5
curl https://api.sandbase.ai/v1/chat/completions \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-opus-5.5",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

To run the same prompt on Gemini 4 Argon, change "model" to google/gemini-4-argon. Nothing else changes, so you can A/B both on your own prompts before committing.

Both models

Pricing, playground and reference for each.

Anthropic

Claude Opus 5.5

anthropic/claude-opus-5.5

Claude Opus 5.5 is the most powerful model in the Claude 5 family from Anthropic. It excels at complex reasoning, analysis, and creative tasks with superior accuracy and nuance. It supports text, image, and file inputs with text output, reasoning support and a 1M-token context window.

Google

Gemini 4 Argon

google/gemini-4-argon

Gemini 4 Argon is Google's flagship reasoning model and the first model of the Gemini 4 generation, generally available since October 13, 2026. Google trained it to keep context and precision across long, multi-step work such as complex software engineering, legal and financial research, and cybersecurity defense. It accepts text, image, video, audio and PDF input with a 1M-token context window, always reasons before answering with low, medium or high effort, and supports function calling and structured output.

FAQ

Which is cheaper, Claude Opus 5.5 or Gemini 4 Argon?

On SandBase Claude Opus 5.5 is $3.80 per 1M input tokens and $19 per 1M output tokens; Gemini 4 Argon is $4 and $20. Claude Opus 5.5 has the lower output price.

Is Claude Opus 5.5 better than Gemini 4 Argon?

On the Artificial Analysis Intelligence Index Claude Opus 5.5 scores 57.6 and Gemini 4 Argon scores 52.6, so Claude Opus 5.5 is ahead on general capability. Cost and speed can point the other way, so check the table above for the metric that matters to your workload.

What does each model cost per task?

Artificial Analysis measures $5.98 per task for Claude Opus 5.5 and $1.99 for Gemini 4 Argon, running the same Intelligence Index workload. That figure folds in how many tokens each model spends on reasoning, so it tracks real spend better than the per-token price alone.

How big is the context window of each model?

Claude Opus 5.5 accepts 1M tokens and Gemini 4 Argon accepts 1M tokens per request.

Can I use both Claude Opus 5.5 and Gemini 4 Argon with one API key?

Yes. Both run through SandBase, so a single API key and balance covers them and the rest of the catalog. You do not need separate Anthropic and Google developer accounts.

How do I switch between Claude Opus 5.5 and Gemini 4 Argon?

Change the model field in your request from "anthropic/claude-opus-5.5" to "google/gemini-4-argon". The endpoint, key and request shape stay the same, which makes it cheap to A/B the two on your own prompts.

Where do these benchmark numbers come from?

The Intelligence, Coding and Agentic indexes, cost per task and output speed come from Artificial Analysis, from the snapshot dated 2026-10-14. Prices are SandBase list prices after any public discount. Numbers move as new snapshots land.

Keep comparing

See all comparisons, browse the language model catalog, or check the full Artificial Analysis leaderboards in SandBase Lab.