Claude Sonnet 5.5 vs Gemma 4 26B A4B (Workers AI)
Reading a 26.2K-token pull request costs $0.0524 on Claude Sonnet 5.5, 20× the $0.0026 it costs on Gemma 4 26B A4B (Workers AI). Claude Sonnet 5.5 is a mid-range model and Gemma 4 26B A4B (Workers AI) a economy one. In the benchmark Claude Sonnet 5.5 caught 51 percentage points more of the known defects than Gemma 4 26B A4B (Workers AI) (95% interval +35 pts to +66 pts, a − b).
Side by side
| Figure | Claude Sonnet 5.5 | Gemma 4 26B A4B (Workers AI) |
|---|---|---|
| Price tier | Mid-range | Economy |
| Bugs caughtshare of known bugs | 77% (better) | 26% |
| False alarmsper clean PR | 2.0 | 0.4 (better) |
| Cost per reviewmeasured | $0.0571 | $0.0048 (better) |
| Cost per bug caught | $0.083 | $0.0209 (better) |
| Exact linecatches on the expected lines | 82% | 91% (better) |
| Review timemean | 11s (better) | 308s |
| Typical review calllist price | $0.0766 | $0.0033 (better) |
| Input / 1M tokens | $2.00 | $0.10 (better) |
| Output / 1M tokens | $10.00 | $0.30 (better) |
| Context window | 1M | 256K |
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 Sonnet 5.5 | 77% | 83% | 50% | 45% | 100% | 56% | 100% | 67% | 67% | 67% | 100% | 100% | 100% | 100% |
| Gemma 4 26B A4B (Workers AI) | 26% | 33% | 0% | 30% | 38% | 7% | 0% | 56% | 33% | 44% | 67% | 0% | 0% | 0% |
Of the 42 known bugs both were scored on, both caught 14 and neither caught 7. Claude Sonnet 5.5 caught 19 bugs that Gemma 4 26B A4B (Workers AI) missed: 3 in JavaScript, 3 in Swift, 2 in C++, 2 in Go, 2 in Rust, 2 in TypeScript, 1 in C, 1 in C#, 1 in Java, 1 in PHP and 1 in Ruby. Gemma 4 26B A4B (Workers AI) caught 2 bugs that Claude Sonnet 5.5 missed: 1 in Java and 1 in Kotlin.
On pull requests with no known bug, Claude Sonnet 5.5 raised 2 false alarms per review and Gemma 4 26B A4B (Workers AI) 0.4. A measured review cost $0.0571 on Claude Sonnet 5.5, 12× the cost of $0.0048 on Gemma 4 26B A4B (Workers AI).
| Pull request | Language · kind | Claude Sonnet 5.5 | Gemma 4 26B A4B (Workers AI) |
|---|---|---|---|
| OrchardCMS/OrchardCoreSimplify using `StringValues` in Liquid templates | C# · Security | 1/1 | 0/3 |
| better-auth/better-authfix(saml): IdP-Initiated Callback Routing | TypeScript · Security | 2/2 | 0/2 |
| 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 | 1/1 | 0/4 |
| colinhacks/zodfeat(v4): parse input containing reference cycles | TypeScript · Resource handling | 1/1 | 0/2 |
| duckdb/duckdbFix vsize = 2 issue in JSON create | C++ · Concurrency | 1/1 | 0/3 |
| ggml-org/llama.cpprpc : cache and reuse compute graphs | C++ · Security | 1/1 | 0/3 |
| go-chi/chifeat: middleware.ClientIP, a replacement for middleware.RealIP | Go · Security | 1/1 | 0/3 |
| golang/gocrypto/tls: add LocalCertificate to ConnectionState | Go · Logic | 1/1 | 0/3 |
| groue/GRDB.swiftDatabaseQueue and DatabaseSnapshot reads can access task locals | Swift · Concurrency | 1/1 | 0/2 |
| mockito/mockitoAdd core API to enable Kotlin singleton mocking | Java · API misuse | 1/1 | 0/3 |
| nodejs/undicifeat: add configurable maxPayloadSize for WebSocket | JavaScript · Security | 1/1 | 0/3 |
| nushell/nushellreorganize nushell configuration | Rust · Error handling | 1/1 | 0/2 |
| pinojs/thread-streamrefactor: replace setTimeout with Atomics.waitAsync | JavaScript · Concurrency | 1/1 | 0/4 |
| pointfreeco/swift-composable-architectureRemove child store from parent when invalidated | Swift · Resource handling | 1/1 | 0/4 |
| pointfreeco/swift-navigationUIKit: Fix switch presented child double dismiss | Swift · Logic | 1/1 | 0/4 |
| sindresorhus/p-throttleAdd `weight` option | JavaScript · Logic | 1/1 | 0/3 |
| socketry/asyncBarrier wait in completion order + `Queue#close`. | Ruby · Concurrency | 1/1 | 0/3 |
| symfony/symfony[Security] Allow multiple OIDC discovery endpoints | PHP · Security | 1/1 | 0/3 |
| tokio-rs/tokiotime: move lazy-registration state into `Sleep` | Rust · Logic | 1/1 | 0/2 |
| iBotPeaches/Apktoolrefactor: Improve renaming/injection of resources in stripped APKs | Java · Security | 0/1 | 3/3 |
| ktorio/ktorKTOR-9171 Redesign ByteReadChannel.readUTF8Line API | Kotlin · Logic | 0/1 | 1/3 |
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 Sonnet 5.5 and Gemma 4 26B A4B (Workers AI).