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Grok-4 Fast Reasoning vs Grok Code Fast 1

Comparing Grok-4 Fast Reasoning and Grok Code Fast 1 across benchmarks, pricing, and capabilities.

xAI · xAI · Updated for 2026

Which is better?

Grok-4 Fast Reasoning and Grok Code Fast 1 trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

On price, Grok-4 Fast Reasoning is roughly 1.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok-4 Fast Reasoning also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.

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

Choose Grok-4 Fast Reasoning

  • cost matters — it's about 1.9x cheaper per token
  • you process long inputs — it offers a 2,000,000 token context window

Choose Grok Code Fast 1

  • you want predictable pricing at $0.20/M input and $1.50/M output

At a glance

The differences that matter most.

Grok-4 Fast Reasoning
xAI
Grok Code Fast 1
xAI
Benchmark wins
—
—
Input price
$0.20 / M
$0.20 / M
Output price
$0.50 / M
$1.50 / M
Context window
2,000,000
256,000

Individual benchmarks

0 reported for Grok-4 Fast Reasoning · 1 for Grok Code Fast 1

No common benchmarks found

Grok-4 Fast Reasoning and Grok Code Fast 1don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Grok-4 Fast Reasoning costs less

For input processing, Grok-4 Fast Reasoning ($0.20/1M tokens) costs the same as Grok Code Fast 1 ($0.20/1M tokens).

For output processing, Grok-4 Fast Reasoning ($0.50/1M tokens) is 3.0x cheaper than Grok Code Fast 1 ($1.50/1M tokens).

In conclusion, Grok Code Fast 1 is more expensive than Grok-4 Fast Reasoning.*

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

Lowest available price from all providers
Thu Sep 10 2026 • llm-stats.com
xAI
Grok-4 Fast Reasoning
Input tokens$0.20
Output tokens$0.50
Best providerxAI
xAI
Grok Code Fast 1
Input tokens$0.20
Output tokens$1.50
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok-4 Fast Reasoning accepts 2,000,000 input tokens compared to Grok Code Fast 1's 256,000 tokens. Grok-4 Fast Reasoning can generate longer responses up to 30,000 tokens, while Grok Code Fast 1 is limited to 10,000 tokens.

xAI
Grok-4 Fast Reasoning
Input2,000,000 tokens
Output30,000 tokens
xAI
Grok Code Fast 1
Input256,000 tokens
Output10,000 tokens
Thu Sep 10 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Grok-4 Fast Reasoning supports multimodal inputs, whereas Grok Code Fast 1 does not.

Grok-4 Fast Reasoning can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok-4 Fast Reasoning

Text
Images
Audio
Video

Grok Code Fast 1

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.

Grok-4 Fast Reasoning

Proprietary

Closed source

Grok Code Fast 1

Proprietary

Closed source

Release Timeline

When each model was launched

Both models were released on 2025-08-28.

They likely represent similar generations of model development.

Grok-4 Fast Reasoning

Aug 28, 2025

1.0 years ago

Grok Code Fast 1

Aug 28, 2025

1.0 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-4 Fast Reasoning is available from xAI. Grok Code Fast 1 is available from xAI.

Grok-4 Fast Reasoning

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $0.50/1M

Grok Code Fast 1

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $1.50/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Grok-4 Fast Reasoning and Grok Code Fast 1 side-by-side, then vote on the output you prefer.

Grok-4 Fast Reasoning
✓ Preferred
Grok Code Fast 1
Open in Playground

FAQ

Common questions about Grok-4 Fast Reasoning vs Grok Code Fast 1.

Which is better, Grok-4 Fast Reasoning or Grok Code Fast 1?

Grok-4 Fast Reasoning (xAI) and Grok Code Fast 1 (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 Grok-4 Fast Reasoning compare to Grok Code Fast 1 in benchmarks?

Grok Code Fast 1 scores SWE-Bench Verified: 70.8%.

Is Grok-4 Fast Reasoning cheaper than Grok Code Fast 1?

Both models cost $0.20 per million input tokens.

What are the context window sizes for Grok-4 Fast Reasoning and Grok Code Fast 1?

Grok-4 Fast Reasoning supports 2.0M tokens and Grok Code Fast 1 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 Grok-4 Fast Reasoning and Grok Code Fast 1?

Key differences include context window (2.0M vs 256K), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

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