Model Comparison

Grok 4.5 vs o3-proWhich is better in 2026?

Comparing Grok 4.5 and o3-pro across benchmarks, pricing, and capabilities.

Verdict: Grok 4.5 vs o3-pro — which is better?

Grok 4.5 (by xAI) and o3-pro (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.

On price, Grok 4.5 is roughly 11.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok 4.5 also accepts a larger context window (500,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Grok 4.5 if…

  • cost matters — it's about 11.7x cheaper per token
  • you process long inputs — it offers a 500,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Choose o3-pro if…

  • you want predictable pricing at $20.00/M input and $80.00/M output

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Grok 4.5 and o3-prodon'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 4.5 costs less

For input processing, Grok 4.5 ($2.00/1M tokens) is 10.0x cheaper than o3-pro ($20.00/1M tokens).

For output processing, Grok 4.5 ($6.00/1M tokens) is 13.3x cheaper than o3-pro ($80.00/1M tokens).

In conclusion, o3-pro is more expensive than Grok 4.5.*

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

Lowest available price from all providers
Sun Jul 26 2026 • llm-stats.com
xAI
Grok 4.5
Input tokens$2.00
Output tokens$6.00
Best providerxAI
OpenAI
o3-pro
Input tokens$20.00
Output tokens$80.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok 4.5 accepts 500,000 input tokens compared to o3-pro's 200,000 tokens. Only o3-pro specifies output context (100,000 tokens).

xAI
Grok 4.5
Input500,000 tokens
Output- tokens
OpenAI
o3-pro
Input200,000 tokens
Output100,000 tokens
Sun Jul 26 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Grok 4.5 and o3-pro support multimodal inputs.

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

Grok 4.5

Text
Images
Audio
Video

o3-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 4.5

Proprietary

Closed source

o3-pro

Proprietary

Closed source

Release Timeline

When each model was launched

Grok 4.5 was released on 2026-07-16, while o3-pro was released on 2025-06-10.

Grok 4.5 is 13 months newer than o3-pro.

Grok 4.5

Jul 16, 2026

1 weeks ago

1.1yr newer
o3-pro

Jun 10, 2025

1.1 years ago

Knowledge Cutoff

When training data ends

Grok 4.5 has a knowledge cutoff of 2026-02-01, while o3-pro has a cutoff of 2024-05-31.

Grok 4.5 has more recent training data (up to 2026-02-01), making it potentially better informed about events through that date compared to o3-pro (2024-05-31).

Grok 4.5

Feb 2026

1.8 yr newer
o3-pro

May 2024

Provider Availability

Grok 4.5 is available from xAI. o3-pro is available from OpenAI.

Grok 4.5

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M

o3-pro

openai logo
OpenAI
Input Price:Input: $20.00/1MOutput Price:Output: $80.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

xAI
Larger context window (500,000 tokens)
Less expensive input tokens
Less expensive output tokens
OpenAI

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

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Grok 4.5 and o3-pro side-by-side, then vote on the output you prefer.

Grok 4.5
✓ Preferred
o3-pro
Open in Playground
AI Model Comparison Table
Feature
xAI
Grok 4.5
OpenAI
o3-pro

FAQ

Common questions about Grok 4.5 vs o3-pro.

Which is better, Grok 4.5 or o3-pro?

Grok 4.5 (xAI) and o3-pro (OpenAI) 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 4.5 compare to o3-pro in benchmarks?

Grok 4.5 scores GPQA: 93.0%, Terminal-Bench 2.1: 83.3%, Artificial Analysis Coding Agent Index v1.1: 76.0%, SWE-Bench Pro: 64.7%, AA-Omniscience Index: 63.0%.

Is Grok 4.5 cheaper than o3-pro?

Grok 4.5 is 10.0x cheaper for input tokens. Grok 4.5 costs $2.00/M input and $6.00/M output via xai. o3-pro costs $20.00/M input and $80.00/M output via openai.

What are the context window sizes for Grok 4.5 and o3-pro?

Grok 4.5 supports 500K tokens and o3-pro supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok 4.5 and o3-pro?

Key differences include context window (500K vs 200K), input pricing ($2.00 vs $20.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok 4.5 and o3-pro?

Grok 4.5 is developed by xAI and o3-pro is developed by OpenAI.

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