GPT-5.5 vs Claude Opus 4.7: Which Frontier Model Should You Use?
Two of the most capable models you can buy, put through the same prompts. One is the better all-rounder for everyday work; the other is who we trust with long, careful tasks.
If you want one model for most things, GPT-5.5 is the easier recommendation: it is quick, broadly capable, and the cheaper of the two. But when the task is long, careful, and code-heavy, Claude Opus 4.7 is the one we trust to hold the thread, which is why it edges ahead overall for the work we care most about.
Round by Round
Across general questions, planning, and quick analysis, GPT-5.5 answered faster and was rarely wrong on the things most people ask day to day. It is the snappier of the two for ordinary work.
On multi-file refactors and long, multi-step tasks, Opus 4.7 stayed on track where GPT-5.5 occasionally lost the plot. It was the one we trusted to finish a hard job without drifting.
Opus 4.7 produced cleaner first drafts that needed less editing, with a steadier tone. GPT-5.5 is strong here too, but we reached for the editing pass less often with Claude.
GPT-5.5 returned answers noticeably faster in our runs, which adds up over a day of back-and-forth. If responsiveness matters most, it wins this round comfortably.
GPT-5.5 costs less per token and ships a usable lower-tier option, so for high-volume or budget-conscious work it is the better value even when the gap in quality is small.
These are two of the strongest general models you can pay for right now, and the honest answer is that most people would be happy with either. The differences show up at the edges: when a task gets long, when latency matters, and when the bill arrives.
How we ran it
We sent both models the same set of prompts across reasoning, coding, and writing, judged the outputs blind where we could, and noted response times and pricing as of testing. We did not use any vendor-supplied benchmarks; everything here comes from our own runs.
The short version
Pick GPT-5.5 if you want one fast, affordable model for a bit of everything. Pick Claude Opus 4.7 if your day is dominated by code and long, careful tasks where staying on track matters more than raw speed. Plenty of teams we know keep both on hand and route the hard jobs to Claude.
Scores and prices move fast in this category. We re-test when a major version ships, so check the date at the top before you treat any of this as final.