+
+
+
+
+
+
+
+
VS
VS
VS
VS
VS
VS
GPT-5 Codex vs GPT-5.1 Instant
Comprehensive side-by-side LLM comparison
GPT-5.1 Instant leads with 1.8% higher average benchmark score. GPT-5.1 Instant supports multimodal inputs. Both models have their strengths depending on your specific coding needs.
+
+
+
+
OpenAI
GPT-5 Codex, released by OpenAI in August 2025, is a coding-specialized large language model from the GPT-5 family engineered for software engineering, code generation, and agentic development workflows. It builds on GPT-5's architecture with optimizations targeting multi-file code editing, test generation, and automated debugging. GPT-5 Codex targets developers and agentic coding tools requiring a model tuned specifically for programming tasks.
+
+
+
+
OpenAI
GPT-5.1 Instant, released by OpenAI in November 2025, is a low-latency variant from the GPT-5.1 family optimized for fast response times and high-throughput workloads. It targets real-time applications, conversational assistants, and production APIs where response speed is a primary requirement alongside GPT-5.1-generation reasoning quality.
3 months newer
GPT-5 Codex
OpenAI
2025-08
GPT-5.1 Instant
OpenAI
2025-11
Average performance across 1 common benchmarks
+
+
+
+
GPT-5 Codex
Average Score:74.5%
+
+
+
+
GPT-5.1 Instant
Average Score:76.3%(+1.8%)
Performance comparison across key benchmark categories
+
+
+
+
GPT-5 Codex
Coding74.5%
+
+
+
+
GPT-5.1 Instant
Coding76.3%(+1.8%)
Provider Availability & Performance
Available providers and their performance metrics
+
+
+
+
GPT-5 Codex
0 providers
+
+
+
+
GPT-5.1 Instant
0 providers
+
+
+
+
GPT-5 Codex
Avg Score:74.5%
Providers:0
+
+
+
+
GPT-5.1 Instant
Avg Score:76.3%(+1.8%)
Providers:0