Claude Opus 4.5 vs Grok-4
Claude Opus 4.5 and Grok-4 are closely matched at 38.3 and 33.9 on the LLM Stats Score. Grok-4 is 1.7x cheaper per token.
Anthropic · xAI · Updated for 2026
Which is better?
Claude Opus 4.5 and Grok-4 are closely matched on the overall LLM Stats Score at 38.3 and 33.9.
The models split the 2 individual benchmarks reported for both models evenly.
On price, Grok-4 is roughly 1.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok-4 also accepts a larger context window (256,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Opus 4.5
- you want the most recent training data — it shipped Nov 2025
Choose Grok-4
- cost matters — it's about 1.7x cheaper per token
- you process long inputs — it offers a 256,000 token context window
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
11 reported for Claude Opus 4.5 · 7 for Grok-4
Claude Opus 4.5 outperforms in 1 benchmarks (ARC-AGI v2), while Grok-4 is better at 1 benchmark (GPQA).
Both models are evenly matched across the benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 1.7x more expensive than Grok-4 ($3.00/1M tokens).
For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 1.7x more expensive than Grok-4 ($15.00/1M tokens).
In conclusion, Claude Opus 4.5 is more expensive than Grok-4.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok-4 accepts 256,000 input tokens compared to Claude Opus 4.5's 200,000 tokens. Claude Opus 4.5 can generate longer responses up to 64,000 tokens, while Grok-4 is limited to 8,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude Opus 4.5 and Grok-4 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Opus 4.5
Grok-4
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Opus 4.5 was released on 2025-11-24, while Grok-4 was released on 2025-07-09.
Claude Opus 4.5 is 5 months newer than Grok-4.
Nov 24, 2025
9 months ago
4mo newerJul 9, 2025
1.2 years ago
Knowledge Cutoff
When training data ends
Claude Opus 4.5 has a knowledge cutoff of 2025-03-31, while Grok-4 has a cutoff of 2024-12-31.
Claude Opus 4.5 has more recent training data (up to 2025-03-31), making it potentially better informed about events through that date compared to Grok-4 (2024-12-31).
Mar 2025
3 mo newerDec 2024
Provider Availability
Claude Opus 4.5 is available from Anthropic. Grok-4 is available from xAI.
Claude Opus 4.5
Grok-4
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Opus 4.5 and Grok-4 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Opus 4.5 vs Grok-4.