Claude Opus 4.6 vs Grok 4

Across our 12-test internal benchmark suite, Claude Opus 4.6 wins four categories outright, Grok 4 wins two, and they tie on six.

Where Opus 4.6 leads:

• Creative problem-solving: Opus 4.6 scores 5/5, tied for 1st among 8 models out of 54 tested. Grok 4 scores 3/5, ranking 30th of 54. This is a substantial gap — Opus 4.6 generated non-obvious, specific, feasible ideas at a meaningfully higher rate in our testing.
• Tool calling: Opus 4.6 scores 5/5, tied for 1st among 17 models out of 54. Grok 4 scores 4/5, ranking 18th of 54. For agentic pipelines where function selection, argument accuracy, and sequencing determine whether a task completes correctly, this difference is operationally significant.
• Agentic planning: Opus 4.6 scores 5/5, tied for 1st among 15 models out of 54. Grok 4 scores 3/5, ranking 42nd of 54 — the bottom quarter of tested models on this dimension. Goal decomposition and failure recovery are where Grok 4 falls furthest behind.
• Safety calibration: Opus 4.6 scores 5/5, tied for 1st among only 5 models out of 55 — a tighter elite group than most categories. Grok 4 scores 2/5, ranking 12th of 55. Safety calibration measures refusal of harmful requests alongside correct permission of legitimate ones; Opus 4.6 handles this balance significantly better in our testing.

Where Grok 4 leads:

• Classification: Grok 4 scores 4/5, tied for 1st among 30 models out of 53. Opus 4.6 scores 3/5, ranking 31st of 53. For routing and categorization tasks, Grok 4 outperforms.
• Constrained rewriting: Grok 4 scores 4/5, ranking 6th of 53. Opus 4.6 scores 3/5, ranking 31st of 53. Grok 4 is noticeably better at compression within hard character limits.

Where they tie: Both models score identically on structured output (4/5), strategic analysis (5/5), faithfulness (5/5), long context (5/5), persona consistency (5/5), and multilingual (5/5).

External benchmarks (Epoch AI): Opus 4.6 scores 78.7% on SWE-bench Verified (Epoch AI), ranking 1st of 12 models with that score in our dataset — the sole holder of that rank. This places it above the 75th percentile benchmark of 75.25% across models we track. On AIME 2025 (Epoch AI), Opus 4.6 scores 94.4%, ranking 4th of 23 models with that data point. Grok 4 has no external benchmark scores in the payload, so direct comparison on SWE-bench or AIME is not possible from this data.

Claude Opus 4.6 costs $5.00/M input and $25.00/M output tokens. Grok 4 costs $3.00/M input and $15.00/M output tokens — a 40% reduction on input and a 40% reduction on output. In practice, output cost dominates most production budgets. At 1M output tokens/month, Opus 4.6 costs $25 versus Grok 4's $15 — a $10 difference that is negligible. At 10M output tokens/month, the gap grows to $100 versus $150, saving $50 with Grok 4. At 100M output tokens/month, Grok 4 saves $1,000 per month ($1,500 vs $2,500). The cost gap matters most to high-volume API consumers — content pipelines, classification systems, or large-scale summarization jobs. For developers running occasional agent tasks or low-volume professional work, the $10/M output premium for Opus 4.6 is unlikely to be the deciding factor. Note that Grok 4 uses reasoning tokens (a documented quirk in the payload), which can inflate token counts depending on how reasoning is configured — factor that into real-world cost estimates.

Choose Claude Opus 4.6 if: You are building or running agentic workflows — especially those involving multi-step tool use, goal decomposition, or failure recovery. Our testing shows a 2-point advantage over Grok 4 on agentic planning (5 vs 3) and a 1-point advantage on tool calling (5 vs 4), which translates directly to more reliable autonomous task completion. Also choose Opus 4.6 if safety calibration matters to your deployment — it scored 5/5 versus Grok 4's 2/5 in our testing, making it significantly more reliable at refusing harmful requests without over-blocking legitimate ones. Its 78.7% SWE-bench Verified score (Epoch AI, ranked 1st of 12 in our dataset) makes it the top coding model by that external measure. Opus 4.6 also accepts a 1M token context window versus Grok 4's 256K, which matters for document-heavy workflows.

Choose Grok 4 if: Your primary workloads are classification, routing, or constrained text compression — Grok 4 ranks 1st on classification and 6th on constrained rewriting in our testing, while Opus 4.6 ranks 31st on both. At $15/M output tokens versus $25/M, Grok 4 also makes more financial sense at high output volumes (100M+ tokens/month, saving $1,000/month). Grok 4 additionally supports file inputs alongside text and images, and exposes logprobs — useful for developers who need probability outputs for downstream processing. If your use case does not depend on complex agentic behavior or strict safety controls, Grok 4 delivers comparable scores on six of twelve benchmarks at a lower price.