Headline indices and pricing

The Czech Institute for AI and Data (CIAD) published July 2026 benchmarks comparing Anthropic’s Claude Opus 5 with SpaceXAI’s Grok 4.5. On the composite Intelligence Index Claude Opus 5 scores 60.7 against Grok 4.5’s 53.8. The Coding Index gap is narrower: 78 for Claude Opus 5 versus 72.4 for Grok 4.5. Price diverges sharply. Claude Opus 5 costs 10 USD per million tokens while Grok 4.5 costs 3 USD per million tokens.

Speed nearly identical

Token generation speed is virtually matched. Claude Opus 5 produces 61.4 tokens per second and Grok 4.5 produces 61.2 tokens per second. Time to first token differs more noticeably: Claude Opus 5 at 32.53 seconds versus Grok 4.5 at 11.38 seconds.

Deep benchmarks reveal task specific strengths

On the Humanity’s Last Exam (HLE) suite measuring expert level multi discipline reasoning Claude Opus 5 achieves 52.6 percent accuracy against Grok 4.5’s 40.3 percent. The GPQA Diamond benchmark of PhD level science questions shows near parity at 93.2 percent for Claude Opus 5 and 93.1 percent for Grok 4.5. Scientific code implementation (SciCode) gives Claude Opus 5 55.7 percent and Grok 4.5 54.1 percent. Long context reasoning (LCR) favours Claude Opus 5 at 70 percent versus 67.7 percent.

Deployment implications

For workloads demanding peak reasoning across scientific research complex analysis or long document processing Claude Opus 5’s higher deep benchmark scores justify its premium. Organisations with constrained budgets or high volume routine tasks such as autonomous agents or terminal based tooling will find Grok 4.5’s 70 percent lower token cost and equivalent throughput more compelling. The time to first token advantage of Grok 4.5 may also matter for interactive latency sensitive applications.

Frequently asked questions

Which model is better for scientific research?

Claude Opus 5 leads in the HLE benchmark with 52.6% accuracy vs 40.3% for Grok 4.5. In GPQA Diamond they are nearly tied, Claude Opus 5 has 93.2%, Grok 4.5 93.1%. Therefore Claude Opus 5 is more suitable for scientific research.

What is the price difference between Claude Opus 5 and Grok 4.5?

Claude Opus 5 costs 10 USD per million tokens, Grok 4.5 only 3 USD. The price difference is therefore significant, which may be decisive for deployments with large token volumes.

Which model is faster?

In generation speed both models are nearly identical: Claude Opus 5 processes 61.4 tokens per second, Grok 4.5 61.2 tokens per second. In time to first token Grok 4.5 is faster with 11.38 seconds vs 32.53 seconds for Claude Opus 5.

DATA SOURCES AND METHOD

Všechna čísla v tomto srovnání pocházejí z uvedených zdrojů k datu 29 July 2026. Grafy generuje institut CIAD přímo ze zdrojových dat; textová analýza čísla nikdy nedopočítává ani neodhaduje.