Model Comparison

Grok Code Fast 1 vs o1-previewWhich is better in 2026?

Grok Code Fast 1 significantly outperforms across most benchmarks. Grok Code Fast 1 is 50.0x cheaper per token.

Verdict: Grok Code Fast 1 vs o1-preview — which is better?

Grok Code Fast 1 (by xAI) and o1-preview (by OpenAI) 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.

Grok Code Fast 1 outperforms in 1 benchmarks (SWE-Bench Verified), while o1-preview is better at 0 benchmarks. Grok Code Fast 1 significantly outperforms across most benchmarks.

On price, Grok Code Fast 1 is roughly 50.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok Code Fast 1 also accepts a larger context window (256,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Grok Code Fast 1 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • cost matters — it's about 50.0x cheaper per token
  • you process long inputs — it offers a 256,000 token context window
  • you want the most recent training data — it shipped Aug 2025

Choose o1-preview if…

  • you want predictable pricing at $15.00/M input and $60.00/M output
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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Grok Code Fast 1 outperforms in 1 benchmarks (SWE-Bench Verified), while o1-preview is better at 0 benchmarks.

Grok Code Fast 1 significantly outperforms across most benchmarks.

Sun Jun 21 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok Code Fast 1 costs less

For input processing, Grok Code Fast 1 ($0.20/1M tokens) is 75.0x cheaper than o1-preview ($15.00/1M tokens).

For output processing, Grok Code Fast 1 ($1.50/1M tokens) is 40.0x cheaper than o1-preview ($60.00/1M tokens).

In conclusion, o1-preview is more expensive than Grok Code Fast 1.*

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

Lowest available price from all providers
Sun Jun 21 2026 • llm-stats.com
xAI
Grok Code Fast 1
Input tokens$0.20
Output tokens$1.50
Best providerxAI
OpenAI
o1-preview
Input tokens$15.00
Output tokens$60.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok Code Fast 1 accepts 256,000 input tokens compared to o1-preview's 128,000 tokens. o1-preview can generate longer responses up to 32,768 tokens, while Grok Code Fast 1 is limited to 10,000 tokens.

xAI
Grok Code Fast 1
Input256,000 tokens
Output10,000 tokens
OpenAI
o1-preview
Input128,000 tokens
Output32,768 tokens
Sun Jun 21 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 Code Fast 1

Proprietary

Closed source

o1-preview

Proprietary

Closed source

Release Timeline

When each model was launched

Grok Code Fast 1 was released on 2025-08-28, while o1-preview was released on 2024-09-12.

Grok Code Fast 1 is 12 months newer than o1-preview.

Grok Code Fast 1

Aug 28, 2025

9 months ago

11mo newer
o1-preview

Sep 12, 2024

1.8 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

Provider Availability

Grok Code Fast 1 is available from xAI. o1-preview is available from OpenAI, Azure.

Grok Code Fast 1

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $1.50/1M

o1-preview

openai logo
OpenAI
Input Price:Input: $15.00/1MOutput Price:Output: $60.00/1M
azure logo
Azure
Input Price:Input: $16.50/1MOutput Price:Output: $66.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

xAI
Larger context window (256,000 tokens)
Less expensive input tokens
Less expensive output tokens
Higher SWE-Bench Verified score (70.8% vs 41.3%)
OpenAI

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

Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok Code Fast 1
OpenAI
o1-preview

FAQ

Common questions about Grok Code Fast 1 vs o1-preview.

Which is better, Grok Code Fast 1 or o1-preview?

Grok Code Fast 1 significantly outperforms across most benchmarks. Grok Code Fast 1 is made by xAI and o1-preview is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok Code Fast 1 compare to o1-preview in benchmarks?

Grok Code Fast 1 scores SWE-Bench Verified: 70.8%. o1-preview scores MGSM: 90.8%, MMLU: 90.8%, MATH: 85.5%, GPQA: 73.3%, LiveBench: 52.3%.

Is Grok Code Fast 1 cheaper than o1-preview?

Grok Code Fast 1 is 75.0x cheaper for input tokens. Grok Code Fast 1 costs $0.20/M input and $1.50/M output via xai. o1-preview costs $15.00/M input and $60.00/M output via openai.

What are the context window sizes for Grok Code Fast 1 and o1-preview?

Grok Code Fast 1 supports 256K tokens and o1-preview supports 128K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok Code Fast 1 and o1-preview?

Key differences include context window (256K vs 128K), input pricing ($0.20 vs $15.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok Code Fast 1 and o1-preview?

Grok Code Fast 1 is developed by xAI and o1-preview is developed by OpenAI.

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