Claude 4.7 vs GPT-5.5 in production: which model wins which job
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 in production workflows.
Long agentic loops, Claude wins
Claude 4.7 in 1M-context mode handles 30-step tool-use loops without drift. Inbox-triage agents that used to need a guardrail layer on GPT-5.0 run steadily on Claude. The 5.5 update closed most of the gap but Claude is still steadier when the loop runs longer than 8 tool calls.
Short structured output, GPT wins
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.
Code-gen and PR review, Claude
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.
Voice and realtime, GPT
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.
The portfolio answer
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.
