Claude Opus 5 Benchmarks: What the Numbers Actually Show
Opus 5 posts 79.2 percent on SWE-bench Pro against Opus 4.8 at 69.2, a 10 point jump with no change in per-token price Anthropic published most gains as ratios (three times ARC-AGI-3, more than double Frontier-Bench) rather than absolute scores On CursorBench 3.2 at max effort it lands within 0.5 percent of Fable 5's peak at half the cost per task Public GDPval-AA figures disagree across sources by up to 117 Elo, so I left that row out entirely Anthropic shipped Claude Opus 5 on July 24, and the coverage filled up with ratios instead of scores. Three times the next-best model. More than double the previous Opus. Just over a third of the cost. I went looking for the actual numbers behind those phrases. What I found says as much about how model launches get reported as it does about the model. The Numbers That Are Actually Comparable The cleanest row is SWE-bench Pro, which runs a model against real GitHub issues and checks whether the patch passes the repository's own tests. It is harder than the older SWE-bench Verified set and it is the row the whole industry now quotes. Model SWE-bench Pro Released Claude Fable 5 80.3 2026-06-09 Claude Opus 5 79.2 2026-07-24 Claude Opus 4.8 69.2 2026-05-29 GPT-5.6 Sol 64.6 2026-07-09 That is a 10 point jump from Opus 4.8 to Opus 5 inside two months, and the per-token price did not move (both tiers run at 5 and 25 per million tokens). Fable 5 keeps a 1.1 point lead and charges double for it. Those two facts together are the actual story of this release, and neither one is a ratio. On SWE-bench Verified, the older and easier set, Opus 5 reports 96.0 percent averaged over five trials. The averaging matters. A single run on a set that saturated above 90 percent tells you very little, because the spread between runs starts to rival the gap between models. Five trials is better practice than most launch tables bother with, and it is worth noticing when a lab does it. It is worth being precise about why those two rows behave differently,