Model Comparison

Claude Opus 5 vs Grok-4Which is better in 2026?

Claude Opus 5 significantly outperforms across most benchmarks. Grok-4 is 1.7x cheaper per token.

Verdict: Claude Opus 5 vs Grok-4 — which is better?

Claude Opus 5 (by Anthropic) and Grok-4 (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 Opus 5 outperforms in 1 benchmarks (Humanity's Last Exam), while Grok-4 is better at 0 benchmarks. Claude Opus 5 significantly outperforms across most benchmarks.

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.

Claude Opus 5 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Claude Opus 5 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Choose Grok-4 if…

  • cost matters — it's about 1.7x cheaper per token

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Opus 5 outperforms in 1 benchmarks (Humanity's Last Exam), while Grok-4 is better at 0 benchmarks.

Claude Opus 5 significantly outperforms across most benchmarks.

Sun Jul 26 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok-4 costs less

For input processing, Claude Opus 5 ($5.00/1M tokens) is 1.7x more expensive than Grok-4 ($3.00/1M tokens).

For output processing, Claude Opus 5 ($25.00/1M tokens) is 1.7x more expensive than Grok-4 ($15.00/1M tokens).

In conclusion, Claude Opus 5 is more expensive than Grok-4.*

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

Lowest available price from all providers
Sun Jul 26 2026 • llm-stats.com
Anthropic
Claude Opus 5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
xAI
Grok-4
Input tokens$3.00
Output tokens$15.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Claude Opus 5 accepts 1,000,000 input tokens compared to Grok-4's 256,000 tokens. Claude Opus 5 can generate longer responses up to 128,000 tokens, while Grok-4 is limited to 8,000 tokens.

Anthropic
Claude Opus 5
Input1,000,000 tokens
Output128,000 tokens
xAI
Grok-4
Input256,000 tokens
Output8,000 tokens
Sun Jul 26 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 5 and Grok-4 support multimodal inputs.

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

Claude Opus 5

Text
Images
Audio
Video

Grok-4

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 Opus 5

Proprietary

Closed source

Grok-4

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5 was released on 2026-07-24, while Grok-4 was released on 2025-07-09.

Claude Opus 5 is 13 months newer than Grok-4.

Claude Opus 5

Jul 24, 2026

1 days ago

1.0yr newer
Grok-4

Jul 9, 2025

1.0 years ago

Knowledge Cutoff

When training data ends

Grok-4 has a documented knowledge cutoff of 2024-12-31, while Claude Opus 5's cutoff date is not specified.

We can confirm Grok-4's training data extends to 2024-12-31, but cannot make a direct comparison without Claude Opus 5's cutoff date.

Claude Opus 5

—

Grok-4

Dec 2024

Provider Availability

Claude Opus 5 is available from Anthropic. Grok-4 is available from xAI.

Claude Opus 5

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

Grok-4

xai logo
xAI
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Larger context window (1,000,000 tokens)
Higher Humanity's Last Exam score (64.7% vs 40.0%)
xAI
Less expensive input tokens
Less expensive output tokens
AnthropicClaude Opus 5
xAIGrok-4
Compare in Playground

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Opus 5 and Grok-4 side-by-side, then vote on the output you prefer.

Claude Opus 5
✓ Preferred
Grok-4
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AI Model Comparison Table
Feature
Anthropic
Claude Opus 5
xAI
Grok-4

FAQ

Common questions about Claude Opus 5 vs Grok-4.

Which is better, Claude Opus 5 or Grok-4?

Claude Opus 5 significantly outperforms across most benchmarks. Claude Opus 5 is made by Anthropic and Grok-4 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 5 compare to Grok-4 in benchmarks?

Claude Opus 5 scores BrowseComp: 90.8%, BioMysteryBench: 90.1%, OSWorld 2.0: 70.6%, DeepSWE 1.1: 68.8%, Humanity's Last Exam: 64.7%. Grok-4 scores AIME 2025: 91.7%, HMMT25: 90.0%, GPQA: 87.5%, LiveCodeBench: 79.0%, Humanity's Last Exam: 40.0%.

Is Claude Opus 5 cheaper than Grok-4?

Grok-4 is 1.7x cheaper for input tokens. Claude Opus 5 costs $5.00/M input and $25.00/M output via anthropic. Grok-4 costs $3.00/M input and $15.00/M output via xai.

What are the context window sizes for Claude Opus 5 and Grok-4?

Claude Opus 5 supports 1.0M tokens and Grok-4 supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 5 and Grok-4?

Key differences include context window (1.0M vs 256K), input pricing ($5.00 vs $3.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5 and Grok-4?

Claude Opus 5 is developed by Anthropic and Grok-4 is developed by xAI.

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