GPT-5 vs GPT-5.1

Both GPT-5 and GPT-5.1 share matched API token pricing at $1.25 per 1M input tokens and $10.00 per 1M output tokens. Because their token economics are identical, your selection should be guided by benchmark latency, memory horizon, and reasoning capabilities rather than operational token fees. Both models support prompt caching discounts of up to 90% for repeated prompt prefixes.

Both GPT-5 and GPT-5.1 offer an identical context window of 400K tokens (~300k words). Both architectures provide equal capacity for large document ingestion, multi-file codebases, and extended multi-turn conversation histories.

Both models achieve an identical 74.9% score on SWE-bench Verified, demonstrating matched software engineering capabilities.

GPT-5 features native chain-of-thought extended thinking mode with configurable reasoning effort. In contrast, GPT-5.1 provides chain-of-thought reasoning depth for complex math and science.

GPT-5 generates approximately 135 tokens per second, while GPT-5.1 delivers 130 tokens per second. In latency-sensitive production environments, GPT-5 provides faster time-to-first-token (TTFT) and higher streaming response velocity.

Yes! Tiered multi-model routing can optimize for latency and accuracy: you can route high-frequency conversational turns and latency-sensitive queries to GPT-5, and route deep architectural or complex reasoning queries to GPT-5. This balanced routing strategy maximizes system throughput and answer quality.