Claude Sonnet 5.5 vs Gemini 4 Argon: price, scores, context

Side-by-side comparison

Criterion	Claude Sonnet 5.5	Gemini 4 Argon
Developer	Anthropic	Google DeepMind
Released	September 28, 2026	October 13, 2026
Capability index	95.9 / 100	95.3 / 100
Input price	$2	$2
Output price	$10	$10
Cost of a typical task	$0.06	$0.06
Context window	1,000,000 tokens	1,048,576 tokens
Maximum output	128,000 tokens	32,768 tokens
Reasoning mode	Yes	Yes
Tool calling	Yes	Yes
Accepted inputs	text, image, PDF	text, image, video, audio, PDF
Open weights	No	No
Knowledge cutoff	June 2026	March 2026

Two models head to head

Claude Sonnet 5.5 and Gemini 4 Argon are two frontier models, the ones you pick when quality comes first, one from Anthropic, the other from Google DeepMind. Claude Sonnet 5.5 was released on September 28, 2026, Gemini 4 Argon on October 13, 2026.

All figures below come from public sources checked on October 22, 2026: models.dev and OpenRouter for prices and capabilities, Epoch AI for scores.

Which one is more capable?

On our capability index, Claude Sonnet 5.5 scores 95.9 out of 100 and Gemini 4 Argon 95.3. The gap is too small to separate them.

On the 5 benchmarks reported for both, Claude Sonnet 5.5 wins 2 times and Gemini 4 Argon 2:

GPQA Diamond (PhD-level science questions): Claude Sonnet 5.5 95.6%, Gemini 4 Argon 96.4%
OTIS Mock AIME (competition mathematics problems): Claude Sonnet 5.5 100%, Gemini 4 Argon 100%
FrontierMath (very hard research-level mathematics): Claude Sonnet 5.5 88.8%, Gemini 4 Argon 86%
FrontierCode (advanced programming tasks): Claude Sonnet 5.5 52.1%, Gemini 4 Argon 47.6%
APEX-Agents (professional tasks carried out by an agent): Claude Sonnet 5.5 75.5%, Gemini 4 Argon 82.4%

Pricing

Claude Sonnet 5.5 costs $2 per million input tokens and $10 per million output tokens; Gemini 4 Argon costs $2 and $10.

For a typical agent task (read 20,000 tokens, write 2,000), expect $0.06 with Claude Sonnet 5.5 versus $0.06 with Gemini 4 Argon. The cost is almost the same.

Run the numbers with your own volumes in the agent cost calculator.

Features and limits

Gemini 4 Argon reads more in one go: 1,048,576 tokens of context (roughly 1,573 pages), versus 1,000,000 for Claude Sonnet 5.5.

Reasoning mode: Claude Sonnet 5.5 yes, Gemini 4 Argon yes. Tool calling: Claude Sonnet 5.5 yes, Gemini 4 Argon yes. Image input: Claude Sonnet 5.5 yes, Gemini 4 Argon yes.

Neither publishes its weights: both are used through an API.

Knowledge cutoff: June 2026 for Claude Sonnet 5.5, March 2026 for Gemini 4 Argon.

In short

On the available data, neither stands out clearly: the right choice depends on your tests and on the provider you already use.

This verdict relies on public figures; it does not replace a trial on your own tasks.

Frequently asked questions

Claude Sonnet 5.5 or Gemini 4 Argon: which is better?

On our index (Epoch AI data), Claude Sonnet 5.5 scores 95.9 and Gemini 4 Argon 95.3 out of 100. The best choice also depends on price and on your use case.

Which one is cheaper?

Claude Sonnet 5.5. To read 20,000 tokens and write 2,000, expect $0.06 with Claude Sonnet 5.5 and $0.06 with Gemini 4 Argon (prices as of October 22, 2026).

Which one has the larger context window?

Gemini 4 Argon, with 1,048,576 tokens versus 1,000,000.

Can I run Claude Sonnet 5.5 or Gemini 4 Argon on my own servers?

No: both are closed models, available through an API.

Claude Sonnet 5.5 or Gemini 4 Argon: which to choose?