Model Comparison

GPT-5 nano vs Grok-4Which is better in 2026?

Grok-4 significantly outperforms across most benchmarks. GPT-5 nano is 43.6x cheaper per token.

Verdict: GPT-5 nano vs Grok-4 — which is better?

GPT-5 nano (by OpenAI) and Grok-4 (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.

GPT-5 nano outperforms in 0 benchmarks, while Grok-4 is better at 3 benchmarks (AIME 2025, GPQA, Humanity's Last Exam). Grok-4 significantly outperforms across most benchmarks.

On price, GPT-5 nano is roughly 43.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5 nano also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose GPT-5 nano if…

  • cost matters — it's about 43.6x cheaper per token
  • you process long inputs — it offers a 400,000 token context window
  • you want the most recent training data — it shipped Aug 2025

Choose Grok-4 if…

  • you want the strongest raw capability — it leads on 3 of 3 shared benchmarks

Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

GPT-5 nano outperforms in 0 benchmarks, while Grok-4 is better at 3 benchmarks (AIME 2025, GPQA, Humanity's Last Exam).

Grok-4 significantly outperforms across most benchmarks.

Tue Jul 14 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5 nano costs less

For input processing, GPT-5 nano ($0.05/1M tokens) is 60.0x cheaper than Grok-4 ($3.00/1M tokens).

For output processing, GPT-5 nano ($0.40/1M tokens) is 37.5x cheaper than Grok-4 ($15.00/1M tokens).

In conclusion, Grok-4 is more expensive than GPT-5 nano.*

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

Lowest available price from all providers
Tue Jul 14 2026 • llm-stats.com
OpenAI
GPT-5 nano
Input tokens$0.05
Output tokens$0.40
Best providerOpenAI
xAI
Grok-4
Input tokens$3.00
Output tokens$15.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5 nano accepts 400,000 input tokens compared to Grok-4's 256,000 tokens. GPT-5 nano can generate longer responses up to 128,000 tokens, while Grok-4 is limited to 8,000 tokens.

OpenAI
GPT-5 nano
Input400,000 tokens
Output128,000 tokens
xAI
Grok-4
Input256,000 tokens
Output8,000 tokens
Tue Jul 14 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5 nano and Grok-4 support multimodal inputs.

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

GPT-5 nano

Text
Images
Audio
Video

Grok-4

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.

GPT-5 nano

Proprietary

Closed source

Grok-4

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5 nano was released on 2025-08-07, while Grok-4 was released on 2025-07-09.

GPT-5 nano is 1 month newer than Grok-4.

GPT-5 nano

Aug 7, 2025

11 months ago

4w newer
Grok-4

Jul 9, 2025

1.0 years ago

Knowledge Cutoff

When training data ends

GPT-5 nano has a knowledge cutoff of 2024-05-30, while Grok-4 has a cutoff of 2024-12-31.

Grok-4 has more recent training data (up to 2024-12-31), making it potentially better informed about events through that date compared to GPT-5 nano (2024-05-30).

GPT-5 nano

May 2024

Grok-4

Dec 2024

7 mo newer

Provider Availability

GPT-5 nano is available from OpenAI. Grok-4 is available from xAI.

GPT-5 nano

openai logo
OpenAI
Input Price:Input: $0.05/1MOutput Price:Output: $0.40/1M

Grok-4

xai logo
xAI
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (400,000 tokens)
Less expensive input tokens
Less expensive output tokens
xAI
Higher AIME 2025 score (91.7% vs 85.2%)
Higher GPQA score (87.5% vs 71.2%)
Higher Humanity's Last Exam score (40.0% vs 8.7%)
OpenAIGPT-5 nano
xAIGrok-4
Compare in Playground

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-5 nano and Grok-4 side-by-side, then vote on the output you prefer.

GPT-5 nano
✓ Preferred
Grok-4
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5 nano
xAI
Grok-4

FAQ

Common questions about GPT-5 nano vs Grok-4.

Which is better, GPT-5 nano or Grok-4?

Grok-4 significantly outperforms across most benchmarks. GPT-5 nano is made by OpenAI and Grok-4 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT-5 nano compare to Grok-4 in benchmarks?

GPT-5 nano scores AIME 2025: 85.2%, HMMT 2025: 75.6%, GPQA: 71.2%, FrontierMath: 9.6%, Humanity's Last Exam: 8.7%. Grok-4 scores AIME 2025: 91.7%, HMMT25: 90.0%, GPQA: 87.5%, LiveCodeBench: 79.0%, Humanity's Last Exam: 40.0%.

Is GPT-5 nano cheaper than Grok-4?

GPT-5 nano is 60.0x cheaper for input tokens. GPT-5 nano costs $0.05/M input and $0.40/M output via openai. Grok-4 costs $3.00/M input and $15.00/M output via xai.

What are the context window sizes for GPT-5 nano and Grok-4?

GPT-5 nano supports 400K tokens and Grok-4 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 GPT-5 nano and Grok-4?

Key differences include context window (400K vs 256K), input pricing ($0.05 vs $3.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5 nano and Grok-4?

GPT-5 nano is developed by OpenAI and Grok-4 is developed by xAI.

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