Head to head
Claude Opus 5.5 vs Gemini 4 Argon
Which is better, Claude Opus 5.5 or Gemini 4 Argon?
Claude Opus 5.5 finishes ahead of Gemini 4 Argon on the index, 92.8 to 90.6, and leads on all four scores: craft, speed, control and value. Both are scored on the same rubric, in the same week, and neither placing is sponsored.
Updated
Claude Opus 5.5
01 of 73
92.8
Fable-level answers for less than the Opus it replaces. The new default.
Gemini 4 Argon
03 of 73
90.6
Top of the human-preference leaderboard, and almost nobody can use it yet.
The four scores, side by side
| Score | Claude Opus 5.5 | Gemini 4 Argon | Difference |
|---|---|---|---|
| Craft | 98 | 97 | +1 |
| Speed | 84 | 78 | +6 |
| Control | 91 | 84 | +7 |
| Value | 84 | 84 | — |
| Index score | 92.8 | 90.6 | +2.2 |
Which to pick
Claude Opus 5.5 is the safer pick on every axis we score. Gemini 4 Argon earns its place in the index, but nothing in these four numbers argues for it over Claude Opus 5.5.
Claude Opus 5.5
Opus 5.5 reset the top of this index. Anthropic says it performs at the level of Fable 5.1 while costing less than Opus 5, and the independent leaderboards agree: it tops the Artificial Analysis index and sits second on the human-preference arena. It keeps the million-token window and runs long agent loops without drifting. If you want one paid model and no further decisions this quarter, this is it.
Where it shines
- Highest score on the Artificial Analysis index as of October 2026
- Matches the Fable tier on long agentic work at under half its price
- A fast mode for interactive work, in research preview
Gemini 4 Argon
Gemini 4 Argon is Google's new flagship, announced on 30 September and first on the arena leaderboard, though that rating is still marked preliminary. Google says it leads on real-world coding and enterprise automation. Access is rolling out to cyber-defence partners first, with paid API customers promised it as soon as possible, so it is listed here on the strength of independent results rather than anything you can build on today. The announced introductory price is aggressive for a model at this level.
Where it shines
- First on the arena leaderboard as of 8 October
- Leads Google's published coding and automation benchmarks
- An introductory price of two dollars in and ten out is low for this tier