GPT-5.3-Codex

Frontier

OpenAI•Released on 2025-12-18

OpenAI's coding-optimized model, surpassing Claude on SWE-bench. HN users praise its coding value and much more generous quotas than Claude. Ideal for intensive coding work.

71
Overall Score

Core Specs

256K
Context Window
64K
Max Output
✓
Reasoning
✗
Open Source
Multimodal Support
text

Scenario Scores

Coding
#2 / 893
Writing
#8 / 860
Translation
#8 / 865
Data Analysis
#6 / 878
Conversation
#8 / 860
Image Gen
#8 / 850

Pros & Cons

Pros

  • +Coding-optimized
  • +Great value
  • +Generous quotas
  • +SWE-bench leader

Cons

  • −Text-only
  • −Weak at creative tasks
  • −Requires Codex-specific API

Pricing

Input (per 1M tokens)$2.00
Output (per 1M tokens)$8.00
Subscription$20/month
Free trial available
Updated on 2026-03-06

Available In

Codex CLI
OpenAI
Cursor
Anysphere
Cline
Open Source
GitHub Copilot
GitHub/Microsoft

Compare with Others

GPT-5.3-Codex vs GPT-5.4 →GPT-5.3-Codex vs GPT-5.4 Thinking →GPT-5.3-Codex vs Claude Opus 4.6 →

Benchmarks

sweBench76.3%
humanEval97.2%
aiderPolyglot88%