+
+
+
+
+
+
+
+
VS
VS
VS
VS
VS
VS
GPT-5.1 Codex Max vs GPT-OSS-20B
Comprehensive side-by-side LLM comparison
. Both models have their strengths depending on your specific coding needs.
+
+
+
+
OpenAI
GPT-5.1 Codex Max, released by OpenAI in November 2025, is an enhanced coding variant from the GPT-5.1 Codex line, designed for more complex software engineering tasks requiring additional reasoning depth. It targets large-scale code generation, automated refactoring, and sophisticated agentic development workflows.
+
+
+
+
OpenAI
GPT-OSS-20B is an open-weight large language model with 20 billion parameters from OpenAI's open-source model initiative. It targets deployments requiring a smaller, efficient model that can run on consumer or mid-tier hardware while maintaining strong reasoning and coding capabilities relative to its size.
2 months newer
GPT-OSS-20B
OpenAI
2025-08-05
GPT-5.1 Codex Max
OpenAI
2025-11
Performance Metrics
Context window and performance specifications
Provider Availability & Performance
Available providers and their performance metrics
+
+
+
+
GPT-5.1 Codex Max
0 providers
+
+
+
+
GPT-OSS-20B
1 providers
Hugging Face
+
+
+
+
GPT-5.1 Codex Max
Avg Score:0.0%
Providers:0
+
+
+
+
GPT-OSS-20B
Avg Score:0.0%
Providers:1