+
+
+
+
+
+
+
+
VS
VS
VS
VS
VS
VS
GPT-5 Codex vs o1
Comprehensive side-by-side LLM comparison
GPT-5 Codex leads with 33.5% higher average benchmark score. o1 is available on 2 providers. Overall, GPT-5 Codex is the stronger choice for coding tasks.
+
+
+
+
OpenAI
GPT-5 Codex was developed as a specialized variant of GPT-5 optimized for programming and software development tasks. Built to understand and generate code across multiple programming languages, it serves developers with enhanced capabilities for code completion, debugging, translation, and explanation of complex codebases.
+
+
+
+
OpenAI
o1 was developed as part of OpenAI's reasoning-focused model series, designed to spend more time thinking before responding. Built to excel at complex reasoning tasks in science, coding, and mathematics, it employs extended internal reasoning processes to solve harder problems than traditional language models through careful step-by-step analysis.
9 months newer
o1
OpenAI
2024-12-17
GPT-5 Codex
OpenAI
2025-09-15
+
+
+
+
+
+
+
+
+
+
+
+
Performance Metrics
Context window and performance specifications
Average performance across 1 common benchmarks
+
+
+
+
GPT-5 Codex
Average Score:74.5%(+33.5%)
+
+
+
+
o1
Average Score:41.0%
Performance comparison across key benchmark categories
+
+
+
+
GPT-5 Codex
Coding74.5%(+33.5%)
+
+
+
+
o1
Coding41.0%
+
+
+
+
Knowledge Cutoff
Training data recency comparison
GPT-5 Codex
2024-09-30
More recent knowledge cutoff means awareness of newer technologies and frameworks
Provider Availability & Performance
Available providers and their performance metrics
+
+
+
+
GPT-5 Codex
0 providers
+
+
+
+
o1
2 providers
Azure
Throughput:
+
+
+
+
GPT-5 Codex
Avg Score:74.5%(+33.5%)
Providers:0
+
+
+
+
o1
Avg Score:41.0%
Providers:2