GPT-3.5 TurbovsGPT-5 Codex
GPT-5 Codex is the newer model, released after GPT-3.5 Turbo.
| Spec | GPT-3.5 Turbo | GPT-5 Codex |
|---|---|---|
| Input price | $1.5/M tokens | — |
| Output price | $2/M tokens | — |
| Context window | 16K tokens | — |
| Weights | Closed | — |
| Free API (OpenRouter) | No | No |
| Released | Mar 2022 | Sep 2025 |
Our Verdict
GPT-5 Codex
GPT-3.5 TurboRunner-up
Not enough votes to call it. On the specs, GPT-5 Codex has the edge: bigger model tier, newer.
Too close to call
Reviewing agent-written code?See a Brief PR report
API pricing
Cost per 1M tokens
GPT-3.5 Turbo
Input
$1.50
Output
$2.00
GPT-5 Codex
Input
—
Output
—
Where to run it
1 host
GPT-3.5 Turbo1 host
GPT-5 Codex
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 11 Sep 2026.
Writing DNA
Style Comparison
Similarity
67%
GPT-5 Codex uses 14.6x more emoji
GPT-3.5 Turbo
GPT-5 Codex
60%Vocabulary64%
30wSentence Length17w
0.49Hedging0.38
0.3Bold2.3
3.1Lists3.5
0.00Emoji0.15
0.00Headings0.49
0.20Transitions0.05
Based on 28 + 13 text responses
Research
What we learned reading every model
FAQ
Common questions
Keep exploring
More comparisons
GPT-3.5 Turbo vs Ox AlphaNew provider
GPT-3.5 Turbo vs Claude Opus 4New provider
GPT-3.5 Turbo vs Claude Opus 4.1New provider
GPT-3.5 Turbo vs Gemini 2.5 Pro (I/O Edition)New provider
GPT-3.5 Turbo vs GPT-5.4 NanoSame lab
GPT-3.5 Turbo vs GPT-5.4 ProSame lab
GPT-3.5 Turbo vs GPT-5.5Same lab
GPT-3.5 Turbo vs GPT-5.6 LunaVersion compare