Claude Sonnet 5.5 vs Gemini 4 Argon
Claude Sonnet 5.5 and Gemini 4 Argon charge practically the same to read a 26.2K-token pull request ($0.0524). From 2026-12-01, after a scheduled reprice, Claude Sonnet 5.5 becomes the cheaper one. Both sit in the mid-range price tier, so the choice between them is about review quality more than budget. The benchmark cannot separate their recall: Claude Sonnet 5.5 minus Gemini 4 Argon is −5 pts (95% interval −21 pts to +12 pts).
Side by side
| Figure | Claude Sonnet 5.5 | Gemini 4 Argon |
|---|---|---|
| Price tier | Mid-range | Mid-range |
| Bugs caughtshare of known bugs | 77% | 82% (better) |
| False alarmsper clean PR | 2.0 | 1.1 (better) |
| Cost per reviewmeasured | $0.0571 | $0.0527 (better) |
| Cost per bug caught | $0.083 | $0.0706 (better) |
| Exact linecatches on the expected lines | 82% (better) | 78% |
| Review timemean | 11s (better) | 99s |
| Typical review calllist price | $0.0766 | $0.0766 |
| Input / 1M tokens | $2.00 | $2.00 |
| Output / 1M tokens | $10.00 | $10.00 |
| Context window | 1M | 1M |
- From 2026-12-01, after a scheduled reprice, Claude Sonnet 5.5 is the cheaper of the two.
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% |
| Gemini 4 Argon | 82% | 83% | 50% | 83% | 75% | 89% | 67% | 100% | 100% | 83% | 100% | 100% | 100% | 0% |
Of the 42 known bugs both were scored on, both caught 28 and neither caught 1. Claude Sonnet 5.5 caught 5 bugs that Gemini 4 Argon missed: 1 in C, 1 in Go, 1 in JavaScript, 1 in Rust and 1 in TypeScript. Gemini 4 Argon caught 8 bugs that Claude Sonnet 5.5 missed: 2 in Java, 1 in C#, 1 in Go, 1 in Kotlin, 1 in PHP, 1 in Python and 1 in TypeScript, most of them logic bugs.
On pull requests with no known bug, Claude Sonnet 5.5 raised 2 false alarms per review and Gemini 4 Argon 1.1. A measured review cost $0.0571 on Claude Sonnet 5.5, 8% more than $0.0527 on Gemini 4 Argon.
| Pull request | Language · kind | Claude Sonnet 5.5 | Gemini 4 Argon |
|---|---|---|---|
| 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 | 0/1 |
| colinhacks/zodfeat(v4): parse input containing reference cycles | TypeScript · Resource handling | 1/1 | 0/1 |
| golang/gocrypto/tls: add LocalCertificate to ConnectionState | Go · Logic | 1/1 | 0/1 |
| nodejs/undicifeat: add configurable maxPayloadSize for WebSocket | JavaScript · Security | 1/1 | 0/1 |
| nushell/nushellreorganize nushell configuration | Rust · Error handling | 1/1 | 0/1 |
| TanStack/queryfix(query-core): fix hydration bugs for already resolved promises | TypeScript · Logic | 0/1 | 1/1 |
| aio-libs/aiohttpkeep websocket compression state across interleaved control frames | Python · Logic | 0/1 | 1/1 |
| doctrine/ormFix collection filtering API for IN/NOT IN comparisons that require type conversions | PHP · Logic | 0/1 | 1/1 |
| dotnet/orleansfix(serialization): cap codec allocations | C# · Logic | 0/1 | 1/1 |
| iBotPeaches/Apktoolrefactor: Improve renaming/injection of resources in stripped APKs | Java · Security | 0/1 | 1/1 |
| jhy/jsoupStore cached child els in Attributes, not field | Java · Concurrency | 0/2 | 1/2 |
| ktorio/ktorKTOR-9171 Redesign ByteReadChannel.readUTF8Line API | Kotlin · Logic | 0/1 | 1/1 |
| traefik/traefikAdd the option to define custom cipher suites for backend serversTransport | Go · API misuse | 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 Sonnet 5.5 and Gemini 4 Argon.