Model Comparison
GPT-4.5 vs GPT-5 nanoWhich is better in 2026?
GPT-5 nano significantly outperforms across most benchmarks. GPT-5 nano is 681.8x cheaper per token.
Verdict: GPT-4.5 vs GPT-5 nano — which is better?
GPT-4.5 (by OpenAI) and GPT-5 nano (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 GPT-5 nano is better at 1 benchmark (GPQA). GPT-5 nano significantly outperforms across most benchmarks.
On price, GPT-5 nano is roughly 681.8x 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-4.5 if…
- you want predictable pricing at $75.00/M input and $150.00/M output
Choose GPT-5 nano if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- cost matters — it's about 681.8x 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
Performance Benchmarks
Comparative analysis across standard metrics
GPT-4.5 outperforms in 0 benchmarks, while GPT-5 nano is better at 1 benchmark (GPQA).
GPT-5 nano significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-4.5 ($75.00/1M tokens) is 1500.0x more expensive than GPT-5 nano ($0.05/1M tokens).
For output processing, GPT-4.5 ($150.00/1M tokens) is 375.0x more expensive than GPT-5 nano ($0.40/1M tokens).
In conclusion, GPT-4.5 is more expensive than GPT-5 nano.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5 nano accepts 400,000 input tokens compared to GPT-4.5's 128,000 tokens. GPT-5 nano can generate longer responses up to 128,000 tokens, while GPT-4.5 is limited to 4,096 tokens.
Input Capabilities
Supported data types and modalities
Both GPT-4.5 and GPT-5 nano support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-4.5
GPT-5 nano
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-4.5 was released on 2025-02-27, while GPT-5 nano was released on 2025-08-07.
GPT-5 nano is 5 months newer than GPT-4.5.
Feb 27, 2025
1.4 years ago
Aug 7, 2025
1.0 years ago
5mo newerKnowledge Cutoff
When training data ends
GPT-5 nano has a documented knowledge cutoff of 2024-05-30, while GPT-4.5's cutoff date is not specified.
We can confirm GPT-5 nano's training data extends to 2024-05-30, but cannot make a direct comparison without GPT-4.5's cutoff date.
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May 2024
Provider Availability
GPT-4.5 is available from OpenAI. GPT-5 nano is available from OpenAI.
GPT-4.5
GPT-5 nano
Outputs Comparison
Key Takeaways
GPT-4.5
View detailsOpenAI
No standout differentiators in the data we have for this pair.
GPT-5 nano
View detailsOpenAI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-4.5 and GPT-5 nano side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-4.5 vs GPT-5 nano.