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Grok-1.5 vs o1

o1 leads the LLM Stats Score 21.1 to -2.5.

xAI · OpenAI · Updated for 2026

Which is better?

o1 leads the overall LLM Stats Score 21.1 to -2.5, ranking #182 overall.

In the 7 individual benchmarks reported for both models, o1 wins 7; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Grok-1.5

  • you are already invested in the xAI ecosystem

Choose o1

  • overall performance matters — it scores 21.1 and ranks #182 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 7 of 7 exact shared results
  • you want the most recent training data — it shipped Dec 2024

At a glance

The differences that matter most.

Grok-1.5
xAI
o1
OpenAI
Core performance indexes
LLM Stats Score
-2.5
#328
21.1
#182
Reasoning
-2.0
#318
21.4
#171
Coding
-0.8
#237
4.8
#197
Cost, coverage & limits
Benchmark wins
0 of 7
7 of 7
Input price
— / M
$15.00 / M
Output price
— / M
$60.00 / M
Context window
—
200,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

3 shared
Index
Grok-1.5
o1
Math
5.4#266
24.1#114
Vision
-4.8#197
13.0#96
Multimodal
-2.2#156
16.9#76
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

9 reported for Grok-1.5 · 19 for o1

7 shared

Grok-1.5 outperforms in 0 benchmarks, while o1 is better at 7 benchmarks (GPQA, GSM8k, HumanEval, MATH, MathVista, MMLU, MMMU).

o1 significantly outperforms across most benchmarks.

Fri Sep 04 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only o1 specifies input context (200,000 tokens). Only o1 specifies output context (100,000 tokens).

xAI
Grok-1.5
Input- tokens
Output- tokens
OpenAI
o1
Input200,000 tokens
Output100,000 tokens
Fri Sep 04 2026 • llm-stats.com

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Grok-1.5

Proprietary

Closed source

o1

Proprietary

Closed source

Release Timeline

When each model was launched

Grok-1.5 was released on 2024-03-28, while o1 was released on 2024-12-17.

o1 is 9 months newer than Grok-1.5.

Grok-1.5

Mar 28, 2024

2.4 years ago

o1

Dec 17, 2024

1.7 years ago

8mo newer

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→

Judge for yourself.

Run your own prompts against Grok-1.5 and o1 side-by-side, then vote on the output you prefer.

Grok-1.5
✓ Preferred
o1
Open in Playground

FAQ

Common questions about Grok-1.5 vs o1.

Which is better, Grok-1.5 or o1?

o1 leads the LLM Stats Score 21.1 to -2.5. Grok-1.5 is made by xAI and o1 is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Grok-1.5 compare to o1 in benchmarks?

Grok-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%. o1 scores GSM8k: 97.1%, MATH: 96.4%, GPQA Physics: 92.8%, MMLU: 91.8%, MGSM: 89.3%.

What are the context window sizes for Grok-1.5 and o1?

Grok-1.5 supports an unknown number of tokens and o1 supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok-1.5 and o1?

Key differences include LLM Stats Score (-2.5 vs 21.1). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-1.5 and o1?

Grok-1.5 is developed by xAI and o1 is developed by OpenAI.

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