After 3 months of running both in parallel for client workloads, here is the cheat sheet for when to pick which model, by task and not by benchmark.
Benchmark posts are easy. Production posts are useful. Here is what we actually pick for which job in May 2026, after running Claude 4.7 (Anthropic) and GPT-5.5 (OpenAI) side by side on real client traffic for 90 days.
Claude 4.7 in 1M-context mode handles 30-step tool-use loops without drift. We have inbox-triage agents running 200+ classifications per day on Claude that used to need a guardrail layer on GPT-5.0. The 5.5 update closed most of the gap but Claude is still steadier when the loop runs longer than 8 tool calls.
For a single-call “extract these 12 fields from this PDF”, GPT-5.5 with response_format=json_schema is faster and cheaper. We default to GPT for OCR + extraction unless the document is over 80 pages.
Claude 4.7 still produces cleaner refactors on real codebases. Lower hallucination rate on imports and types. GPT-5.5 is closer than 5.0 was, but our agents still pick Claude for the diff-suggestion job.
OpenAI shipped GPT-Realtime-2 on May 7 and it is the only production-grade voice-to-voice model with sub-200ms latency in this price tier. Claude has no realtime API yet.
Almost every production stack we build uses both. Route by job, not by vendor. Our AI integration work increasingly looks like a model-router layer plus a thin shell of business logic, not a one-vendor commitment.