GPT-4.5vso3 Mini
o3 Mini is cheaper than GPT-4.5 at $1.1/M vs $75/M input tokens.
| Spec | GPT-4.5 | o3 Mini |
|---|---|---|
| Input price | $75/M tokens | $1.1/M tokens |
| Output price | $150/M tokens | $4.4/M tokens |
| Context window | 128K tokens | 64K tokens |
| Parameters | Not disclosed | Not disclosed |
| Weights | — | Closed |
| Free API (OpenRouter) | No | No |
| Released | Feb 2025 | Dec 2024 |
| MMLU | 90.8% | 85.9% |
Our Verdict
GPT-4.5
o3 MiniRunner-up
Not enough votes to call it. On the specs, GPT-4.5 has the edge: bigger model tier, newer, bigger context window.
GPT-4.5 wins Reasoning and Image Generation. o3 Mini costs 34x less per token.
Slight edge
Reviewing agent-written code?See a Brief PR report
API pricing
Cost per 1M tokens
GPT-4.5
Input
$75.00
Output
$150.00
o3 Mini
Input
$1.10
68× cheaper
Output
$4.40
34× cheaper
o3 Mini is cheaper on both: 68× input, 34× output.
Where to run it
1 host
GPT-4.5
No hosts listed on OpenRouter.
o3 Mini1 host
Per million tokens. Prices and uptime via OpenRouter, checked 13 Sep 2026.
Writing DNA
Style Comparison
Similarity
58%
GPT-4.5 uses 4.3x more lists
GPT-4.5
o3 Mini
63%Vocabulary65%
16wSentence Length18w
0.57Hedging0.84
4.7Bold2.8
6.4Lists1.5
0.00Emoji0.00
1.30Headings0.33
0.54Transitions0.29
Based on 11 + 17 text responses
Research
What we learned reading every model
FAQ
