Model Horizon
Dashboard
Models
Compare
Benchmarks
Search
Ctrl K
Skip to content
Home
/
Models
/
GPT-5.3 Codex
GPT-5.3 Codex
OpenAI · Frontier tier
GPT-5.3 Codex
O
OpenAI
frontier
Release Date: Feb 5, 2026
1480
Arena Elo
81
GPQA
96
MATH
93
HumanEval
93
MMLU
80
SWE-bench
Try GPT-5.3 Codex
Specifications
Context Window
400K tokens
Max Output
128K tokens
Input Price
$1.75 per million
Output Price
$14 per million
Release Date
February 5, 2026
Tier
Frontier
Capabilities
vision
tool-use
code
reasoning
agentic
Benchmarks
Arena Elo
1480
MMLU
93
GPQA
81
MATH
96
HumanEval
93
SWE-bench
80
AIME
94
SimpleQA
58
Cost Estimate
Input Tokens
500K
Output Tokens
100K
Estimated Cost
$2.2750
Input: $0.8750
Output: $1.4000
Related Models
O
GPT-5.2
OpenAI · Elo 1438
frontier
O
GPT-5.1
OpenAI · Elo 1458
frontier
O
o3
OpenAI · Elo 1433
frontier
O
o4-mini
OpenAI · Elo 1380
frontier
Compare With
GPT-5.3 Codex vs Gemini 3.1 Pro
GPT-5.3 Codex vs Claude Opus 4.6
GPT-5.3 Codex vs Gemini 3 Pro