Comprehensive side-by-side LLM comparison
. Both models have their strengths depending on your specific coding needs.
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.
OpenAI
OpenAI o3, released by OpenAI in April 2025, is a large reasoning model that applies extended chain-of-thought processing to deliver improved performance on complex math, science, and coding tasks. It features a 200K token context window and native image understanding, with demonstrated strong results on mathematics and software engineering benchmarks. o3 targets demanding analytical and engineering tasks where deliberate, multi-step reasoning produces significantly better outcomes than direct generation.
6 months newer

o3
OpenAI
2025-04-16

GPT-5.1 Instant
OpenAI
2025-11
Context window and performance specifications
Available providers and their performance metrics
GPT-5.1 Instant
o3
OpenAI
GPT-5.1 Instant
o3
GPT-5.1 Instant
o3