Claude Opus 5.5 vs GPT-6.1 Sol
Reading a 26.2K-token pull request costs $0.1048 on Claude Opus 5.5, 2.0× the $0.0524 it costs on GPT-6.1 Sol. Claude Opus 5.5 is a frontier model and GPT-6.1 Sol a mid-range one. The benchmark cannot separate their recall: Claude Opus 5.5 minus GPT-6.1 Sol is +1 pt (95% interval −9 pts to +11 pts).
Side by side
| Figure | Claude Opus 5.5 | GPT-6.1 Sol |
|---|---|---|
| Price tier | Frontier | Mid-range |
| Bugs caughtshare of known bugs | 90% (better) | 89% |
| False alarmsper clean PR | 1.7 | 0.9 (better) |
| Cost per reviewmeasured | $0.1525 | $0.0401 (better) |
| Cost per bug caught | $0.1921 | $0.0514 (better) |
| Exact linecatches on the expected lines | 89% | 95% (better) |
| Review timemean | 33s | 28s (better) |
| Typical review calllist price | $0.1532 | $0.0766 (better) |
| Input / 1M tokens | $4.00 | $2.00 (better) |
| Output / 1M tokens | $20.00 | $10.00 (better) |
| Context window | 1M | 1.1M |
- Above 272K tokens, long-context rates mean the two cost the same.
Head to head
The known bugs both were scored on, by who caught each in at least one run.
By language
| Model | All | TypeScript6 bugs | Go4 bugs | Java4 bugs | Rust4 bugs | C#3 bugs | JavaScript3 bugs | Kotlin3 bugs | PHP3 bugs | Python3 bugs | Ruby3 bugs | Swift3 bugs | C++2 bugs | C1 bug |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Claude Opus 5.5 | 90% | 100% | 50% | 78% | 100% | 100% | 100% | 67% | 100% | 100% | 89% | 100% | 100% | 100% |
| GPT-6.1 Sol | 89% | 83% | 75% | 70% | 100% | 89% | 100% | 100% | 100% | 100% | 100% | 100% | 50% | 100% |
Of the 42 known bugs both were scored on, both caught 36 and neither caught 1. Claude Opus 5.5 caught 3 bugs that GPT-6.1 Sol missed: 1 in C++, 1 in Java and 1 in TypeScript, most of them concurrency bugs. GPT-6.1 Sol caught 2 bugs that Claude Opus 5.5 missed: 1 in Go and 1 in Kotlin.
On pull requests with no known bug, Claude Opus 5.5 raised 1.7 false alarms per review and GPT-6.1 Sol 0.9. A measured review cost $0.1525 on Claude Opus 5.5, 3.8× the cost of $0.0401 on GPT-6.1 Sol.
| Pull request | Language · kind | Claude Opus 5.5 | GPT-6.1 Sol |
|---|---|---|---|
| ggml-org/llama.cpprpc : cache and reuse compute graphs | C++ · Security | 1/1 | 0/1 |
| trpc/trpcfix(server): pass maxDurationMs timeout signal to subscription handlers | TypeScript · Concurrency | 1/1 | 0/1 |
| jhy/jsoupStore cached child els in Attributes, not field | Java · Concurrency | 1/2 | 0/2 |
| go-chi/chifeat: middleware.ClientIP, a replacement for middleware.RealIP | Go · Security | 0/1 | 1/1 |
| kotest/kotestFix DataClassEq comparator | Kotlin · Logic | 0/1 | 1/1 |
Defects caught over all runs: a PR reviewed three times with one known bug shows 3/3 when it was caught every time.
Every bug each was scored on: Claude Opus 5.5 and GPT-6.1 Sol.