Claude Sonnet 5 vs Grok 4.5
Head-to-head specifications
| Metric | Claude Sonnet 5 | Grok 4.5 | Difference |
|---|---|---|---|
| Intelligence Index | 53.0 | 54.0 | -1.9% |
| Coding Index | 71.5 | 72.4 | -1.2% |
| Agentic Index | 46.7 | 45.7 | — |
| Context window | 1M tokens | 922K tokens | — |
| Blended price ($/1M tokens) | $0.90 | $0.87 | +3.4% |
| Output speed (tokens/s) | 71 | 118 | -39.8% |
| Access | Proprietary API | Proprietary API | — |
- Grok 4.5 leads overall capability (Intelligence Index 54.0 vs 53.0).
- Both cost about the same to run (~$0.87/1M blended tokens), so capability and speed should decide.
- Claude Sonnet 5 offers the larger context window (1M tokens), useful for long documents and codebases.
Verdict: Claude Sonnet 5 or Grok 4.5?
Claude Sonnet 5 advantages
- Context window (+8%)
Grok 4.5 advantages
- Output speed (+40%)
Which should you choose?
- Choose the Claude Sonnet 5 if you work with long documents or large codebases.
- Choose the Grok 4.5 if low latency and fast generation matter for your application.
Value for money
Grok 4.5 offers more intelligence per dollar (1.1× the Intelligence-Index-per-cost of the alternative), making it the stronger value for high-volume use.
Claude Sonnet 5 vs Grok 4.5: which should you choose?
Claude Sonnet 5 — Anthropic multimodal model with an Intelligence Index of 53, a 1M-token context window and a blended price of $0.9/1M tokens.
Grok 4.5 — xAI multimodal model with an Intelligence Index of 54, a 922K-token context window and a blended price of $0.87/1M tokens.
Claude Sonnet 5 vs Grok 4.5: Grok 4.5 scores higher on the Intelligence Index. Grok 4.5 leads overall capability (Intelligence Index 54.0 vs 53.0). Both cost about the same to run (~$0.87/1M blended tokens), so capability and speed should decide.
Capability: intelligence, coding and agentic work
On the composite Intelligence Index the Grok 4.5 scores 54.0 versus 53.0. For software development, the Coding Index puts Grok 4.5 ahead (72.4 vs 71.5). On agentic, multi-step tool-use tasks, Claude Sonnet 5 measures stronger. Composite indices summarize many evaluations, but always test on your own workload before committing.
Context window and speed
The Claude Sonnet 5 accepts up to 1 million tokens per request, which sets how much documentation, transcript or code it can reason over at once. In measured throughput, Grok 4.5 generates faster (118 vs 71 tokens/s), which matters for interactive apps and high-volume pipelines.
Pricing and access
At blended per-token rates, Grok 4.5 is the cheaper model to run ($0.87 vs $0.90 per 1M tokens). Claude Sonnet 5 is proprietary api and Grok 4.5 is proprietary api. Open-weight models can be self-hosted, trading per-call cost for infrastructure you manage; for production also weigh rate limits, throughput and data-residency requirements.
The verdict
Both are credible choices in the ai model comparison space; the specification table above lays out every metric so you can weigh the trade-offs that matter to you. Pick the one whose strengths line up with how you will actually use it.
Frequently asked questions
Is the Claude Sonnet 5 better than the Grok 4.5?
These two are closely matched — the right pick comes down to which specific strengths you value and the price you actually pay. Grok 4.5 leads overall capability (Intelligence Index 54.0 vs 53.0).
What is the main difference between the Claude Sonnet 5 and the Grok 4.5?
Grok 4.5 leads overall capability (Intelligence Index 54.0 vs 53.0). Both cost about the same to run (~$0.87/1M blended tokens), so capability and speed should decide.
Which is better value?
Grok 4.5 offers more intelligence per dollar (1.1× the Intelligence-Index-per-cost of the alternative), making it the stronger value for high-volume use.
Which should I choose?
Choose the Claude Sonnet 5 if you work with long documents or large codebases. Choose the Grok 4.5 if low latency and fast generation matter for your application.
Methodology
Large language models are compared on independent leaderboard metrics: an Intelligence Index (a composite of reasoning and knowledge evaluations), Coding and Agentic indices where measured, community arena Elo, maximum context window, a blended API price per million tokens (weighted across cache-hit, input and output rates), and measured output speed in tokens per second. Where a model ships multiple reasoning-effort variants, we report its strongest variant. Benchmarks capture only part of real-world quality, which also depends on tool use, latency, safety and task fit — and this space moves quickly, so figures reflect the leaderboard snapshot on the page date.