Model Comparison

Grok-4 Fast Reasoning vs Nova ProWhich is better in 2026?

Comparing Grok-4 Fast Reasoning and Nova Pro across benchmarks, pricing, and capabilities.

Verdict: Grok-4 Fast Reasoning vs Nova Pro — which is better?

Grok-4 Fast Reasoning (by xAI) and Nova Pro (by Amazon) 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.

On price, Grok-4 Fast Reasoning is roughly 5.1x 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.

Choose Grok-4 Fast Reasoning if…

  • cost matters — it's about 5.1x cheaper per token
  • you process long inputs — it offers a 2,000,000 token context window
  • you want the most recent training data — it shipped Aug 2025

Choose Nova Pro if…

  • you want predictable pricing at $0.80/M input and $3.20/M output
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

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

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok-4 Fast Reasoning costs less

For input processing, Grok-4 Fast Reasoning ($0.20/1M tokens) is 4.0x cheaper than Nova Pro ($0.80/1M tokens).

For output processing, Grok-4 Fast Reasoning ($0.50/1M tokens) is 6.4x cheaper than Nova Pro ($3.20/1M tokens).

In conclusion, Nova Pro is more expensive than Grok-4 Fast Reasoning.*

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

Lowest available price from all providers
Sun Jun 07 2026 • llm-stats.com
xAI
Grok-4 Fast Reasoning
Input tokens$0.20
Output tokens$0.50
Best providerxAI
Amazon
Nova Pro
Input tokens$0.80
Output tokens$3.20
Best providerAWS Bedrock
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 Nova Pro's 300,000 tokens. Nova Pro can generate longer responses up to 300,000 tokens, while Grok-4 Fast Reasoning is limited to 30,000 tokens.

xAI
Grok-4 Fast Reasoning
Input2,000,000 tokens
Output30,000 tokens
Amazon
Nova Pro
Input300,000 tokens
Output300,000 tokens
Sun Jun 07 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Grok-4 Fast Reasoning and Nova Pro support multimodal inputs.

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

Grok-4 Fast Reasoning

Text
Images
Audio
Video

Nova Pro

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

Nova Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Grok-4 Fast Reasoning was released on 2025-08-28, while Nova Pro was released on 2024-11-20.

Grok-4 Fast Reasoning is 9 months newer than Nova Pro.

Grok-4 Fast Reasoning

Aug 28, 2025

9 months ago

9mo newer
Nova Pro

Nov 20, 2024

1.5 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. Nova Pro is available from Bedrock.

Grok-4 Fast Reasoning

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

Nova Pro

bedrock logo
AWS Bedrock
Input Price:Input: $0.80/1MOutput Price:Output: $3.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

xAI
Larger context window (2,000,000 tokens)
Less expensive input tokens
Less expensive output tokens
Amazon

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

Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok-4 Fast Reasoning
Amazon
Nova Pro

FAQ

Common questions about Grok-4 Fast Reasoning vs Nova Pro.

Which is better, Grok-4 Fast Reasoning or Nova Pro?

Grok-4 Fast Reasoning (xAI) and Nova Pro (Amazon) 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 Nova Pro in benchmarks?

Nova Pro scores ARC-C: 94.8%, GSM8k: 94.8%, DocVQA: 93.5%, IFEval: 92.1%, ChartQA: 89.2%.

Is Grok-4 Fast Reasoning cheaper than Nova Pro?

Grok-4 Fast Reasoning is 4.0x cheaper for input tokens. Grok-4 Fast Reasoning costs $0.20/M input and $0.50/M output via xai. Nova Pro costs $0.80/M input and $3.20/M output via bedrock.

What are the context window sizes for Grok-4 Fast Reasoning and Nova Pro?

Grok-4 Fast Reasoning supports 2.0M tokens and Nova Pro supports 300K 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 Nova Pro?

Key differences include context window (2.0M vs 300K), input pricing ($0.20 vs $0.80/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-4 Fast Reasoning and Nova Pro?

Grok-4 Fast Reasoning is developed by xAI and Nova Pro is developed by Amazon.

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