Model Comparison

GPT-3.5 Turbo vs GPT-5 CodexWhich is better in 2026?

Comparing GPT-3.5 Turbo and GPT-5 Codex across benchmarks, pricing, and capabilities.

Verdict: GPT-3.5 Turbo vs GPT-5 Codex — which is better?

GPT-3.5 Turbo (by OpenAI) and GPT-5 Codex (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.

Choose GPT-3.5 Turbo if…

  • you want predictable pricing at $0.50/M input and $1.50/M output

Choose GPT-5 Codex if…

  • you want the most recent training data — it shipped Sep 2025
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GPT-3.5 Turbo and GPT-5 Codexdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GPT-3.5 Turbo specifies input context (16,385 tokens). Only GPT-3.5 Turbo specifies output context (4,096 tokens).

OpenAI
GPT-3.5 Turbo
Input16,385 tokens
Output4,096 tokens
OpenAI
GPT-5 Codex
Input- tokens
Output- tokens
Mon Jun 15 2026 • llm-stats.com

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

GPT-3.5 Turbo

Proprietary

Closed source

GPT-5 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-3.5 Turbo was released on 2023-03-21, while GPT-5 Codex was released on 2025-09-15.

GPT-5 Codex is 30 months newer than GPT-3.5 Turbo.

GPT-3.5 Turbo

Mar 21, 2023

3.2 years ago

GPT-5 Codex

Sep 15, 2025

9 months ago

2.5yr newer

Knowledge Cutoff

When training data ends

GPT-3.5 Turbo has a knowledge cutoff of 2021-09-30, while GPT-5 Codex has a cutoff of 2024-09-30.

GPT-5 Codex has more recent training data (up to 2024-09-30), making it potentially better informed about events through that date compared to GPT-3.5 Turbo (2021-09-30).

GPT-3.5 Turbo

Sep 2021

GPT-5 Codex

Sep 2024

3 yr newer

Outputs Comparison

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Key Takeaways

OpenAI
Larger context window (16,385 tokens)
OpenAI

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

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-3.5 Turbo
OpenAI
GPT-5 Codex

FAQ

Common questions about GPT-3.5 Turbo vs GPT-5 Codex.

Which is better, GPT-3.5 Turbo or GPT-5 Codex?

GPT-3.5 Turbo (OpenAI) and GPT-5 Codex (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 GPT-3.5 Turbo compare to GPT-5 Codex in benchmarks?

GPT-3.5 Turbo scores DROP: 70.2%, MMLU: 69.8%, HumanEval: 68.0%, MGSM: 56.3%, MATH: 43.1%. GPT-5 Codex scores SWE-Bench Verified: 74.5%.

What are the context window sizes for GPT-3.5 Turbo and GPT-5 Codex?

GPT-3.5 Turbo supports 16K tokens and GPT-5 Codex 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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