Comprehensive side-by-side LLM comparison
o3 leads with 7.8% higher average benchmark score. GPT-5 nano offers 228.0K more tokens in context window than o3. GPT-5 nano is $9.55 cheaper per million tokens. Overall, o3 is the stronger choice for coding tasks.
OpenAI
GPT-5 Nano was developed as the most compact variant in the GPT-5 family, designed for deployment in resource-constrained environments and edge computing scenarios. Built to bring next-generation AI capabilities to devices and applications where latency and efficiency are paramount, it distills GPT-5 innovations into a minimal footprint.
OpenAI
o3 represents the next generation in OpenAI's reasoning model series, developed to advance the capabilities of deliberate, step-by-step problem solving. Built to handle increasingly complex challenges across mathematics, science, and coding, it continues the evolution of reasoning-focused AI with improved analytical depth and accuracy.
3 months newer

o3
OpenAI
2025-04-16

GPT-5 nano
OpenAI
2025-08-07
Cost per million tokens (USD)

GPT-5 nano

o3
Context window and performance specifications
Average performance across 4 common benchmarks

GPT-5 nano

o3
GPT-5 nano
2024-05-30
o3
2024-05-31
Available providers and their performance metrics

GPT-5 nano
OpenAI
ZeroEval


GPT-5 nano

o3

GPT-5 nano

o3
o3
OpenAI