Model Comparison

GPT-4.5 vs o1-proWhich is better in 2026?

o1-pro significantly outperforms across most benchmarks.

Verdict: GPT-4.5 vs o1-pro — which is better?

GPT-4.5 (by OpenAI) and o1-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.

GPT-4.5 outperforms in 0 benchmarks, while o1-pro is better at 2 benchmarks (AIME 2024, GPQA). o1-pro significantly outperforms across most benchmarks.

Choose GPT-4.5 if…

  • you want the most recent training data — it shipped Feb 2025

Choose o1-pro if…

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
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Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

GPT-4.5 outperforms in 0 benchmarks, while o1-pro is better at 2 benchmarks (AIME 2024, GPQA).

o1-pro significantly outperforms across most benchmarks.

Thu Jun 25 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GPT-4.5 specifies input context (128,000 tokens). Only GPT-4.5 specifies output context (4,096 tokens).

OpenAI
GPT-4.5
Input128,000 tokens
Output4,096 tokens
OpenAI
o1-pro
Input- tokens
Output- tokens
Thu Jun 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-4.5 and o1-pro support multimodal inputs.

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

GPT-4.5

Text
Images
Audio
Video

o1-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.

GPT-4.5

Proprietary

Closed source

o1-pro

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-4.5 was released on 2025-02-27, while o1-pro was released on 2024-12-17.

GPT-4.5 is 2 months newer than o1-pro.

GPT-4.5

Feb 27, 2025

1.3 years ago

2mo newer
o1-pro

Dec 17, 2024

1.5 years ago

Knowledge Cutoff

When training data ends

o1-pro has a documented knowledge cutoff of 2023-09-30, while GPT-4.5's cutoff date is not specified.

We can confirm o1-pro's training data extends to 2023-09-30, but cannot make a direct comparison without GPT-4.5's cutoff date.

GPT-4.5

—

o1-pro

Sep 2023

Outputs Comparison

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Key Takeaways

OpenAI
Larger context window (128,000 tokens)
OpenAI
Higher AIME 2024 score (86.0% vs 36.7%)
Higher GPQA score (79.0% vs 69.5%)

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-4.5
OpenAI
o1-pro

FAQ

Common questions about GPT-4.5 vs o1-pro.

Which is better, GPT-4.5 or o1-pro?

o1-pro significantly outperforms across most benchmarks. GPT-4.5 is made by OpenAI and o1-pro is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT-4.5 compare to o1-pro in benchmarks?

GPT-4.5 scores GSM8k: 97.0%, MMLU: 90.8%, CharXiv-D: 90.0%, IFEval: 88.2%, HumanEval: 88.0%. o1-pro scores AIME 2024: 86.0%, GPQA: 79.0%.

What are the context window sizes for GPT-4.5 and o1-pro?

GPT-4.5 supports 128K tokens and o1-pro supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

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