Gemini 4 Carbon vs Claude Opus 5.5
Gemini 4 Carbon leads 14 of 16 shared benchmarks, while Claude Opus 5.5 is the one you can use today.
Choose Claude Opus 5.5 for work you need running today, because Gemini 4 Carbon is limited to Fairwind partners. At Layer3Labs, we build launch guides for new artificial intelligence (AI) models and route client workloads across vendors, so we weigh reported scores against what developers can actually use. Claude Opus 5.5 also leads OSWorld-2.1 computer use, at 87.2% against 81.5%.
Google announced Gemini 4 Carbon on October 28, 2026, describing it as its strongest frontier model with state-of-the-art cybersecurity and long-horizon capabilities. Anthropic released Claude Opus 5.5 on September 22, 2026, offering general availability across its API, hosted cloud providers, and end-user applications.
Gemini 4 Carbon vs. Claude Opus 5.5: Side-by-Side
| Dimension | Gemini 4 Carbon | Claude Opus 5.5 |
|---|---|---|
| Availability | Restricted Fairwind Program partners as of October 28, 2026 | Generally available on API, cloud platforms, and apps |
| AA Intelligence Index v5.0 | 59 (ranked #1 of 52 models on Artificial Analysis) | 58 |
| FrontierSWE 2 | 61.2% | 62.3% |
| OSWorld-2.1 | 81.5% (offline subset) | 87.2% (offline subset) |
| Terminal-Bench 4.0 | 65.2% | 59.6% |
| GraphWalks | 96.2% (BFS, F1, 256k to 1M tokens) | 66.8% (BFS, F1, 256k to 1M tokens) |
| ExploitGym | 54.8% | 34.5% |
| Price per 1M tokens (input/output) | $2 input and $10 output at launch ($4 and $20 after introductory period) | $4 input and $20 output |
| Cost of 1M input + 200k output | $4.00 at launch ($8.00 after introductory period) | $8.00 standard API ($4.00 Message Batches) |
| Best for | Defensive cybersecurity teams with Fairwind partner access | Live production software engineering and autonomous desktop computer use |
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Carbon Scores Higher, Opus 5.5 Ships Today
On Google's published table, Gemini 4 Carbon beats Claude Opus 5.5 on 14 of the 16 benchmarks both report, but Opus 5.5 leads OSWorld-2.1 computer use at 87.2% compared to 81.5% and is available today. Choose Claude Opus 5.5 for work you need running now and re-test Gemini 4 Carbon when it opens for broader developer use.
Gemini 4 Carbon has the top scores on GraphWalks and ExploitGym, but Google limits access to a subset of cyber defenders and vetted organizations. Claude Opus 5.5 is generally available on the Claude API, Amazon Bedrock, Google Cloud and Microsoft Foundry.
Teams looking to use Gemini today can evaluate Gemini 4 Argon, which provides general API availability.
Benchmark Head-to-Head
In our internal analysis of Google's published table, we compared the 16 rows both models report and found Gemini 4 Carbon higher on 14 and Claude Opus 5.5 higher on 2. Google also published scores for SEC-bench Pro, where Gemini 4 Carbon scored 88.2%, but we omitted it from this direct head-to-head table because Google did not report a score for Claude Opus 5.5.
Google evaluated Carbon's external cybersecurity benchmarks without guardrails according to its model announcement. Detailed test criteria and settings are published on Google DeepMind's evaluation methodology page.
A detailed breakdown of Google's reported performance figures is documented in our guide to Gemini 4 Carbon benchmarks.
| Benchmark | Gemini 4 Carbon | Claude Opus 5.5 |
|---|---|---|
| Artificial Analysis Intelligence Index v5.0 | 59 | 58 |
| Vals Index v2.2 | 70.4% | 70.2% |
| SWE-sweep | 9.6% | 3.6% |
| FrontierSWE 2 | 61.2% | 62.3% |
| Terminal-Bench 4.0 | 65.2% | 59.6% |
| Agents' Last Exam v1.1 | 77.4% | 71.6% |
| OSWorld-2.1 (offline subset) | 81.5% | 87.2% |
| AutomationBench (Zapier) | 53.9% | 42.5% |
| GraphWalks 256k to 1M tokens (BFS, F1) | 96.2% | 66.8% |
| CWE-bench | 71.0% | 67.0% |
| ExploitGym | 54.8% | 34.5% |
| Vending-Bench 2 (final bank balance) | $16,484 | $9,235 |
| Chartography | 72.5 | 66.3 |
| Blueprint-Bench 2 | 58.6 | 51.2 |
| RiemannBench | 80.0 | 69.6 |
| Terminal-Bench-Science 0.1 | 64.8 | 59.0 |
Access and Deployment
Claude Opus 5.5 is generally available for production use across multiple platforms, while Gemini 4 Carbon remains restricted to vetted partners as of October 28, 2026. Developers can call Claude Opus 5.5 on the Claude API as claude-opus-5-5. It is also on Amazon Bedrock, Google Cloud, Microsoft Foundry and Claude Platform on Amazon Web Services, as our Claude Opus 5.5 explained guide covers.
Google restricts Gemini 4 Carbon access to a subset of cyber defenders and trusted partners through the Fairwind Program. Priority is given to governments, national cyber authorities, critical infrastructure operators, and core technology platforms, with applications submitted via Google's Fairwind interest form. For broader developer and enterprise access, Google stated the model is coming soon while it gathers feedback and iterates on guardrails, with further background in our Gemini 4 Carbon explained guide.
Carbon is not available in coding tools or integrated development environments (IDEs). The Gemini API models documentation lists gemini-4-argon as the only Gemini 4 model ID as of October 22, 2026. While Artificial Analysis lists Gemini 4 Carbon as available via API through 1 provider, Google's official announcement confirms access remains limited to Fairwind partners.
Cost of 1M Input and 200k Output Tokens
Processing a cumulative workload of 1M input tokens and 200k output tokens costs $4.00 on Gemini 4 Carbon at its launch rate and $8.00 on Claude Opus 5.5 at standard API rates. In our cost analysis, we calculate usage cost using the standard formula: cost equals input tokens multiplied by input rate plus output tokens multiplied by output rate.
At Google's introductory pricing of $2 per 1M input tokens and $10 per 1M output tokens, the math is 1 multiplied by $2 plus 0.2 multiplied by $10, equaling $4.00. When Google's introductory period ends, Carbon will price at $4 input and $20 output per 1M tokens, bringing that exact same volume to $8.00, as detailed in our Gemini 4 Carbon pricing guide.
Claude Opus 5.5 charges $4 per 1M input tokens and $20 per 1M output tokens, so the same usage costs 1 x $4 plus 0.2 x $20, or $8.00. Our Claude Opus 5.5 API pricing guide lists every tier. These figures cover usage spread across many requests, not one prompt.
Claude Opus 5.5 Specifications Anthropic Published
Anthropic released Claude Opus 5.5 on September 22, 2026, with a 1M-token context window and a default 128K maximum output token limit. Through its Message Batches API beta header, Claude Opus 5.5 supports up to 300K maximum output tokens.
Claude Opus 5.5 has adaptive thinking that is always on, so you do not switch it on per request. Its June 2026 knowledge cutoff predates the Gemini 4 Carbon launch. Claude Opus 5.5 is in the Claude apps on Pro, Max, Team and Enterprise plans.
Google has published no context window size, maximum output token limit, or rate limits for Gemini 4 Carbon. Google has also not stated whether Carbon will be offered on a free tier or included in consumer subscription plans.
Where the Score Gaps Are Largest
In our internal analysis, we subtracted each Claude Opus 5.5 score from Gemini 4 Carbon's on the 16 shared rows. Gemini 4 Carbon shows its largest performance leads in graph traversal, vulnerability exploitation, and multi-step workflow automation.
GraphWalks demonstrates the widest gap across the shared benchmark suite. Carbon achieved 96.2% on the breadth-first search F1 evaluation across sequences spanning 256k to 1M tokens, leading Claude Opus 5.5 by 29.4 percentage points. On ExploitGym, Carbon leads by 20.3 percentage points, and on Zapier's AutomationBench, Carbon leads by 11.4 percentage points.
Claude Opus 5.5 leads on two operational benchmarks. On the OSWorld-2.1 offline subset, Opus 5.5 leads by 5.7 percentage points with an 87.2% success rate compared to Carbon's 81.5%. On FrontierSWE 2, Claude Opus 5.5 holds a 1.1 percentage point lead at 62.3% versus 61.2%, while the Vals Index v2.2 differs by only 0.2 percentage points.
| Benchmark | Gemini 4 Carbon | Claude Opus 5.5 | Gap |
|---|---|---|---|
| GraphWalks 256k to 1M tokens (BFS, F1) | 96.2% | 66.8% | +29.4 |
| ExploitGym | 54.8% | 34.5% | +20.3 |
| AutomationBench (Zapier) | 53.9% | 42.5% | +11.4 |
| SWE-sweep | 9.6% | 3.6% | +6.0 |
| Agents' Last Exam v1.1 | 77.4% | 71.6% | +5.8 |
| Terminal-Bench-Science 0.1 | 64.8 | 59.0 | +5.8 |
| Terminal-Bench 4.0 | 65.2% | 59.6% | +5.6 |
| Chartography | 72.5 | 66.3 | +6.2 |
| Blueprint-Bench 2 | 58.6 | 51.2 | +7.4 |
| RiemannBench | 80.0 | 69.6 | +10.4 |
| CWE-bench | 71.0% | 67.0% | +4.0 |
| Artificial Analysis Intelligence Index v5.0 | 59 | 58 | +1.0 |
| Vals Index v2.2 | 70.4% | 70.2% | +0.2 |
| Vending-Bench 2 (final bank balance) | $16,484 | $9,235 | +$7,249 |
| FrontierSWE 2 | 61.2% | 62.3% | -1.1 |
| OSWorld-2.1 (offline subset) | 81.5% | 87.2% | -5.7 |
Batch and Caching Costs
Caching discounts and asynchronous batch processing alter token expenditure for high-volume pipelines. Anthropic offers a 50% discount on Message Batches, pricing Claude Opus 5.5 input tokens at $2 and output tokens at $10 per 1M. For 1M input plus 200k output tokens run asynchronously, the Opus 5.5 Batch cost drops to $4.00.
Anthropic charges $0.20 per 1M tokens for prompt cache hits on Claude Opus 5.5, with cache write operations priced at $5 for 5-minute storage and $8 for 1-hour storage. Google stated that cached input tokens on Gemini 4 Carbon receive a 95% discount, resulting in $0.10 per 1M tokens at launch rates.
Google has published no batch API pricing for Gemini 4 Carbon as of October 28, 2026. Google has also not confirmed whether the 95% cached input discount will continue after the introductory pricing period ends.
Which Model Fits Each Workload
Each model leads a different set of workloads in Google's table. For autonomous desktop interaction and computer-use agents, Claude Opus 5.5 holds a clear 5.7 percentage point lead on the OSWorld-2.1 offline benchmark with an 87.2% success score. Claude Opus 5.5 is generally available for immediate integration.
Software engineering tasks present a narrower divide. Claude Opus 5.5 scored 62.3% on FrontierSWE 2 compared to Carbon's 61.2%, representing a slight 1.1 percentage point advantage. However, Carbon scored higher on terminal operations, reaching 65.2% on Terminal-Bench 4.0 versus Opus 5.5's 59.6%, and 9.6% on SWE-sweep compared to 3.6%.
Security analysis strongly favors Gemini 4 Carbon according to Google's published numbers. Carbon scored 54.8% on ExploitGym compared to Opus 5.5's 34.5%, and reached 71.0% on CWE-bench. On the Gray Swan indirect prompt-injection evaluation, Carbon recorded an attack success rate of 0.0% compared to Argon's 0.7%, though developers cannot deploy Carbon outside the Fairwind Program.
Who Should Not Wait for Gemini 4 Carbon
Teams operating active production workflows, client-facing services, or automated desktop computer-use agents should not wait for Gemini 4 Carbon. Google has announced no public release date for Gemini 4 Carbon. Claude Opus 5.5 can run those workloads today.
If you run your own evaluations, you cannot validate Carbon on internal test suites today without Fairwind access.
Two events would change our recommendation. One is Google opening Gemini 4 Carbon on a public API at its $2 input and $10 output launch rates. The other is Anthropic releasing a new model that closes Carbon's leads on ExploitGym and Terminal-Bench 4.0.
The Verdict
Choose Claude Opus 5.5 if you need a generally available frontier model for computer use or software engineering today. Claude Opus 5.5 leads OSWorld-2.1 at 87.2% and FrontierSWE 2 at 62.3%, and runs on the Claude API, Amazon Bedrock, Google Cloud and Microsoft Foundry.
Apply for Gemini 4 Carbon access through the Fairwind interest form if your organization focuses on defensive cybersecurity, critical infrastructure protection, or security benchmarking, where its ExploitGym score of 54.8% and GraphWalks score of 96.2% offer measurable advantages.
For production pipelines today, keep active workloads running on Claude Opus 5.5 or evaluate Gemini 4 Argon vs Claude Opus 5.5 as the available Google alternative, then queue an evaluation of Gemini 4 Carbon once public API access opens.
Researched from primary vendor documentation and public regulator sources. Pricing and availability are accurate as of Oct 28, 2026 and can change. Confirm current terms with each vendor before you buy.
Frequently Asked Questions
- At launch, Gemini 4 Carbon costs $2 per 1M input tokens and $10 per 1M output tokens, making 1M input plus 200k output tokens cost $4.00. Claude Opus 5.5 costs $4 input and $20 output per 1M tokens, totaling $8.00 for that same usage. When Google's introductory period ends, Carbon prices will rise to $4 input and $20 output, matching Opus 5.5's standard API price.
- Claude Opus 5.5 holds a slight 1.1 percentage point lead on FrontierSWE 2 with 62.3% versus Carbon's 61.2%. Gemini 4 Carbon leads on Terminal-Bench 4.0 with 65.2% versus 59.6% and SWE-sweep with 9.6% versus 3.6%. Because Opus 5.5 is generally available, it is the practical choice for active software engineering today.
- Claude Opus 5.5 leads computer use, scoring 87.2% on the OSWorld-2.1 offline subset compared to Gemini 4 Carbon's 81.5%. It is also generally available for production use today.
- Most developers cannot use Gemini 4 Carbon today. As of October 28, 2026, Google restricts Carbon access to cyber defenders and vetted partners through its Fairwind Program. Claude Opus 5.5 is generally available across the Anthropic API, Amazon Bedrock, Google Cloud, and consumer applications.
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