Model Comparison

Claude Opus 5 vs Grok-1.5Which is better in 2026?

Comparing Claude Opus 5 and Grok-1.5 across benchmarks, pricing, and capabilities.

Verdict: Claude Opus 5 vs Grok-1.5 — which is better?

Claude Opus 5 (by Anthropic) and Grok-1.5 (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.

Choose Claude Opus 5 if…

  • you want the most recent training data — it shipped Jul 2026

Choose Grok-1.5 if…

  • you are already invested in the xAI ecosystem

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Claude Opus 5 and Grok-1.5don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Claude Opus 5 specifies input context (1,000,000 tokens). Only Claude Opus 5 specifies output context (128,000 tokens).

Anthropic
Claude Opus 5
Input1,000,000 tokens
Output128,000 tokens
xAI
Grok-1.5
Input- tokens
Output- tokens
Sat Jul 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Opus 5 supports multimodal inputs, whereas Grok-1.5 does not.

Claude Opus 5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 5

Text
Images
Audio
Video

Grok-1.5

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 Opus 5

Proprietary

Closed source

Grok-1.5

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5 was released on 2026-07-24, while Grok-1.5 was released on 2024-03-28.

Claude Opus 5 is 28 months newer than Grok-1.5.

Claude Opus 5

Jul 24, 2026

0 days ago

2.3yr newer
Grok-1.5

Mar 28, 2024

2.3 years ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Larger context window (1,000,000 tokens)
Supports multimodal inputs
xAI

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

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Opus 5 and Grok-1.5 side-by-side, then vote on the output you prefer.

Claude Opus 5
✓ Preferred
Grok-1.5
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Opus 5
xAI
Grok-1.5

FAQ

Common questions about Claude Opus 5 vs Grok-1.5.

Which is better, Claude Opus 5 or Grok-1.5?

Claude Opus 5 (Anthropic) and Grok-1.5 (xAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Claude Opus 5 compare to Grok-1.5 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-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%.

What are the context window sizes for Claude Opus 5 and Grok-1.5?

Claude Opus 5 supports 1.0M tokens and Grok-1.5 supports an unknown number of 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-1.5?

Key differences include multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5 and Grok-1.5?

Claude Opus 5 is developed by Anthropic and Grok-1.5 is developed by xAI.

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