Model Comparison

Claude 3 Opus vs Grok 4.5Which is better in 2026?

Grok 4.5 significantly outperforms across most benchmarks. Grok 4.5 is 10.0x cheaper per token.

Verdict: Claude 3 Opus vs Grok 4.5 — which is better?

Claude 3 Opus (by Anthropic) and Grok 4.5 (by xAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude 3 Opus outperforms in 0 benchmarks, while Grok 4.5 is better at 1 benchmark (GPQA). Grok 4.5 significantly outperforms across most benchmarks.

On price, Grok 4.5 is roughly 10.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok 4.5 also accepts a larger context window (500,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Claude 3 Opus if…

  • you want predictable pricing at $15.00/M input and $75.00/M output

Choose Grok 4.5 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • cost matters — it's about 10.0x cheaper per token
  • you process long inputs — it offers a 500,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude 3 Opus outperforms in 0 benchmarks, while Grok 4.5 is better at 1 benchmark (GPQA).

Grok 4.5 significantly outperforms across most benchmarks.

Sat Jul 18 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok 4.5 costs less

For input processing, Claude 3 Opus ($15.00/1M tokens) is 7.5x more expensive than Grok 4.5 ($2.00/1M tokens).

For output processing, Claude 3 Opus ($75.00/1M tokens) is 12.5x more expensive than Grok 4.5 ($6.00/1M tokens).

In conclusion, Claude 3 Opus is more expensive than Grok 4.5.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Sat Jul 18 2026 • llm-stats.com
Anthropic
Claude 3 Opus
Input tokens$15.00
Output tokens$75.00
Best providerAnthropic
xAI
Grok 4.5
Input tokens$2.00
Output tokens$6.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok 4.5 accepts 500,000 input tokens compared to Claude 3 Opus's 200,000 tokens. Only Claude 3 Opus specifies output context (200,000 tokens).

Anthropic
Claude 3 Opus
Input200,000 tokens
Output200,000 tokens
xAI
Grok 4.5
Input500,000 tokens
Output- tokens
Sat Jul 18 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude 3 Opus and Grok 4.5 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude 3 Opus

Text
Images
Audio
Video

Grok 4.5

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude 3 Opus

Proprietary

Closed source

Grok 4.5

Proprietary

Closed source

Release Timeline

When each model was launched

Claude 3 Opus was released on 2024-02-29, while Grok 4.5 was released on 2026-07-16.

Grok 4.5 is 29 months newer than Claude 3 Opus.

Claude 3 Opus

Feb 29, 2024

2.4 years ago

Grok 4.5

Jul 16, 2026

2 days ago

2.4yr newer

Knowledge Cutoff

When training data ends

Grok 4.5 has a documented knowledge cutoff of 2026-02-01, while Claude 3 Opus's cutoff date is not specified.

We can confirm Grok 4.5's training data extends to 2026-02-01, but cannot make a direct comparison without Claude 3 Opus's cutoff date.

Claude 3 Opus

—

Grok 4.5

Feb 2026

Provider Availability

Claude 3 Opus is available from Anthropic, Bedrock, Google. Grok 4.5 is available from xAI.

Claude 3 Opus

anthropic logo
Anthropic
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M
bedrock logo
AWS Bedrock
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M
google logo
Google
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M

Grok 4.5

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic

No standout differentiators in the data we have for this pair.

xAI
Larger context window (500,000 tokens)
Less expensive input tokens
Less expensive output tokens
Higher GPQA score (93.0% vs 50.4%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude 3 Opus and Grok 4.5 side-by-side, then vote on the output you prefer.

Claude 3 Opus
✓ Preferred
Grok 4.5
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude 3 Opus
xAI
Grok 4.5

FAQ

Common questions about Claude 3 Opus vs Grok 4.5.

Which is better, Claude 3 Opus or Grok 4.5?

Grok 4.5 significantly outperforms across most benchmarks. Claude 3 Opus is made by Anthropic and Grok 4.5 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude 3 Opus compare to Grok 4.5 in benchmarks?

Claude 3 Opus scores ARC-C: 96.4%, HellaSwag: 95.4%, GSM8k: 95.0%, MGSM: 90.7%, BIG-Bench Hard: 86.8%. Grok 4.5 scores GPQA: 93.0%, Terminal-Bench 2.1: 83.3%, Artificial Analysis Coding Agent Index v1.1: 76.0%, SWE-Bench Pro: 64.7%, AA-Omniscience Index: 63.0%.

Is Claude 3 Opus cheaper than Grok 4.5?

Grok 4.5 is 7.5x cheaper for input tokens. Claude 3 Opus costs $15.00/M input and $75.00/M output via anthropic. Grok 4.5 costs $2.00/M input and $6.00/M output via xai.

What are the context window sizes for Claude 3 Opus and Grok 4.5?

Claude 3 Opus supports 200K tokens and Grok 4.5 supports 500K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude 3 Opus and Grok 4.5?

Key differences include context window (200K vs 500K), input pricing ($15.00 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude 3 Opus and Grok 4.5?

Claude 3 Opus is developed by Anthropic and Grok 4.5 is developed by xAI.

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