Model Comparison

GPT-4.5 vs Grok-4

Grok-4 significantly outperforms across most benchmarks. Grok-4 is 15.6x cheaper per token.

Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

GPT-4.5 outperforms in 0 benchmarks, while Grok-4 is better at 1 benchmark (GPQA).

Grok-4 significantly outperforms across most benchmarks.

Thu Apr 30 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok-4 costs less

For input processing, GPT-4.5 ($75.00/1M tokens) is 25.0x more expensive than Grok-4 ($3.00/1M tokens).

For output processing, GPT-4.5 ($150.00/1M tokens) is 10.0x more expensive than Grok-4 ($15.00/1M tokens).

In conclusion, GPT-4.5 is more expensive than Grok-4.*

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

Lowest available price from all providers
Thu Apr 30 2026 • llm-stats.com
OpenAI
GPT-4.5
Input tokens$75.00
Output tokens$150.00
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

Grok-4 accepts 256,000 input tokens compared to GPT-4.5's 128,000 tokens. Grok-4 can generate longer responses up to 8,000 tokens, while GPT-4.5 is limited to 4,096 tokens.

OpenAI
GPT-4.5
Input128,000 tokens
Output4,096 tokens
xAI
Grok-4
Input256,000 tokens
Output8,000 tokens
Thu Apr 30 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-4.5 and Grok-4 support multimodal inputs.

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

GPT-4.5

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-4.5

Proprietary

Closed source

Grok-4

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-4.5 was released on 2025-02-27, while Grok-4 was released on 2025-07-09.

Grok-4 is 4 months newer than GPT-4.5.

GPT-4.5

Feb 27, 2025

1.2 years ago

Grok-4

Jul 9, 2025

9 months ago

4mo newer

Knowledge Cutoff

When training data ends

Grok-4 has a documented knowledge cutoff of 2024-12-31, while GPT-4.5's cutoff date is not specified.

We can confirm Grok-4's training data extends to 2024-12-31, but cannot make a direct comparison without GPT-4.5's cutoff date.

GPT-4.5

—

Grok-4

Dec 2024

Provider Availability

GPT-4.5 is available from OpenAI. Grok-4 is available from xAI.

GPT-4.5

openai logo
OpenAI
Input Price:Input: $75.00/1MOutput Price:Output: $150.00/1M

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
xAI
Larger context window (256,000 tokens)
Less expensive input tokens
Less expensive output tokens
Higher GPQA score (87.5% vs 69.5%)
OpenAIGPT-4.5
xAIGrok-4
Compare in Playground

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-4.5
xAI
Grok-4

FAQ

Common questions about GPT-4.5 vs Grok-4

Grok-4 significantly outperforms across most benchmarks. GPT-4.5 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.
GPT-4.5 scores GSM8k: 97.0%, MMLU: 90.8%, CharXiv-D: 90.0%, IFEval: 88.2%, HumanEval: 88.0%. Grok-4 scores AIME 2025: 91.7%, HMMT25: 90.0%, GPQA: 87.5%, LiveCodeBench: 79.0%, Humanity's Last Exam: 40.0%.
Grok-4 is 25.0x cheaper for input tokens. GPT-4.5 costs $75.00/M input and $150.00/M output via openai. Grok-4 costs $3.00/M input and $15.00/M output via xai.
GPT-4.5 supports 128K tokens and Grok-4 supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (128K vs 256K), input pricing ($75.00 vs $3.00/M). See the full comparison above for benchmark-by-benchmark results.
GPT-4.5 is developed by OpenAI and Grok-4 is developed by xAI.