Claude Haiku 5.5 vs Kimi K2.7 Code (Workers AI)
Reading a 26.2K-token pull request costs $0.0249 on Kimi K2.7 Code (Workers AI), 9.5× the $0.0026 it costs on Claude Haiku 5.5. Claude Haiku 5.5 is a economy model and Kimi K2.7 Code (Workers AI) a mid-range one. The benchmark cannot separate their recall: Claude Haiku 5.5 minus Kimi K2.7 Code (Workers AI) is +26 pts (95% interval +11 pts to +41 pts).
Side by side
| Figure | Claude Haiku 5.5 | Kimi K2.7 Code (Workers AI) |
|---|---|---|
| Price tier | Economy | Mid-range |
| Bugs caughtshare of known bugs | 64% (better) | 38% |
| False alarmsper clean PR | 1.4 (better) | 2.6 |
| Cost per reviewmeasured | $0.0038 (better) | $0.0567 |
| Cost per bug caught | $0.0064 (better) | $0.0805 |
| Exact linecatches on the expected lines | 82% (better) | 79% |
| Review timemean | 15s (better) | 610s |
| Typical review calllist price | $0.0038 (better) | $0.0346 |
| Input / 1M tokens | $0.10 (better) | $0.95 |
| Output / 1M tokens | $0.50 (better) | $4.00 |
| Context window | 1M | 262.1K |
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 Haiku 5.5 | 64% | 83% | 75% | 40% | 75% | 67% | 33% | 67% | 100% | 39% | 67% | 67% | 50% | 0% |
| Kimi K2.7 Code (Workers AI) | 38% | 75% | 26% | 31% | 46% | 19% | 8% | 14% | 42% | 62% | 33% | 46% | 6% | 40% |
Of the 42 known bugs both were scored on, both caught 26 and neither caught 7. Claude Haiku 5.5 caught 2 bugs that Kimi K2.7 Code (Workers AI) missed: 1 in Ruby and 1 in Rust, all of them concurrency bugs. Kimi K2.7 Code (Workers AI) caught 7 bugs that Claude Haiku 5.5 missed: 1 in C, 1 in Java, 1 in Kotlin, 1 in Python, 1 in Rust, 1 in Swift and 1 in TypeScript, most of them logic bugs.
On pull requests with no known bug, Claude Haiku 5.5 raised 1.4 false alarms per review and Kimi K2.7 Code (Workers AI) 2.6. A measured review cost $0.0038 on Claude Haiku 5.5, 93% less than $0.0567 on Kimi K2.7 Code (Workers AI).
| Pull request | Language · kind | Claude Haiku 5.5 | Kimi K2.7 Code (Workers AI) |
|---|---|---|---|
| denoland/denoperf(libs/core): poll only ready handles and yield between I/O batches | Rust · Concurrency | 1/1 | 0/5 |
| socketry/asyncBarrier wait in completion order + `Queue#close`. | Ruby · Concurrency | 1/1 | 0/5 |
| TanStack/queryfix(query-core): fix hydration bugs for already resolved promises | TypeScript · Logic | 0/1 | 2/3 |
| aio-libs/aiohttpkeep websocket compression state across interleaved control frames | Python · Logic | 0/1 | 2/3 |
| c-ares/c-aresEvent Thread could stall when not notified of new queries on existing connections that are in a bad state | C · Resource handling | 0/1 | 2/5 |
| kotest/kotestFix DataClassEq comparator | Kotlin · Logic | 0/1 | 1/7 |
| mockito/mockitoAdd core API to enable Kotlin singleton mocking | Java · API misuse | 0/1 | 1/8 |
| nushell/nushellreorganize nushell configuration | Rust · Error handling | 0/1 | 2/3 |
| pointfreeco/swift-navigationUIKit: Fix switch presented child double dismiss | Swift · Logic | 0/1 | 2/3 |
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 Haiku 5.5 and Kimi K2.7 Code (Workers AI).