Claude Opus 5.5 vs Gemini 4 Argon
| Benchmark | Opus 5.5 | Gemini 4 Argon |
|---|---|---|
| AutomationBench-AA | 61.2 | 77.5 |
| GDPval-AA (work tasks) 2.1 | 1,593.3 | 1,631.1 |
| AA Analyst Agent | 56.3 · max | 48.8 |
| Terminal-Bench 4.0 | 52.5 | 57.1 |
| Terminal-Bench Science 0.1 | 43.3 | 52.9 |
| AA-Briefcase 1.1 · Elo | 1,620.9 | 1,483.3 |
| AA-LCR (long context) 1.1 | 84.3 | 79.7 |
| FrontierCode 1.1 | 57.1 | 43.5 |
| Harvey LAB-AA 1.1 | 4.2 · max | 3.9 |
| EBR Bench | 71.4 · max | 64.8 |
| Furniture Assembly | 83.3 · max | 72.5 |
| AutomationBench · Zapier run | — | 51.3 |
| ITBench SRE | 38.2 · max | — |
| DeepSWE 1.1 | 72.3 · max | — |
| SWE-bench Pro (v2 full) | — | 99.2 |
| SWE-bench Pro (v2 hard) | — | 92.2 |
| SpireClimb | 3.3 · max | — |
| SpireClimb StS1 A20 Heart | 0 · max | — |
| SpireClimb StS2 A10 | 6.7 · max | — |
Specs
| Spec | Opus 5.5 | Gemini 4 Argon |
|---|---|---|
| Input, per 1M | $4 | !$2 |
| Output, per 1M | $20 | !$10 |
| Cost per task? | $1.34 | $1.62 |
| Speed, tok/s | 82 | 79 |
| Context | 1M | 1M |
| Weights | Closed | Closed |
| Released | Sep 2026 | Oct 2026 |
| See images | ✓ | ✓ |
| Read PDFs | ✓ | ✓ |
| Hear audio | — | ✓ |
| Watch video | — | ✓ |
| Call tools | ✓ | ✓ |
| Force a tool call | — | Partial |
| Return strict JSON | ✓ | ✓ |
| Search the web | ✓ | ✓ |
| Run code | ✓ | ✓ |
| Use a computer | ✓ | ? |
What breaks when you switch
Synchronous output stops at 65,536›
With background false, output limits above 65,536 tokens return HTTP 400; stay at or below that limit.
Sampling parameters are ignored›
temperature, top_p and top_k are ignored; remove them from requests.
No explicit caching›
Explicit caching is unavailable; omit explicit cache requests.
No forced tool use›
Forced tool_choice any or tool returns HTTP 400; remove the forced choice.
Thinking is always on›
Disabled thinking or a manual budget returns HTTP 400; omit thinking or use adaptive thinking.
Remove sampling parameters›
Non-default temperature, top_p or top_k returns HTTP 400; omit these parameters and use prompting.
No assistant prefill›
Assistant prefill returns HTTP 400; use structured outputs or system instructions, with system instructions on Bedrock.
Old computer tool rejected · Claude API / Google Cloud›
The computer_20251124 tool returns HTTP 400 on the Claude API and Google Cloud; use computer_toolset_20260801 there.
Return thinking blocks unmodified›
Edited, reordered or partially dropped thinking blocks return HTTP 400; echo assistant messages complete and unmodified with tool results.