Gemini 3.8 Flash vs GLM-5.3 Flash (Workers AI)
Reading a 26.2K-token pull request costs $0.0197 on Gemini 3.8 Flash, 5.0× the $0.0039 it costs on GLM-5.3 Flash (Workers AI). Gemini 3.8 Flash is a mid-range model and GLM-5.3 Flash (Workers AI) a economy one. The benchmark cannot separate their recall: Gemini 3.8 Flash minus GLM-5.3 Flash (Workers AI) is +7 pts (95% interval −9 pts to +23 pts).
Side by side
| Figure | Gemini 3.8 Flash | GLM-5.3 Flash (Workers AI) |
|---|---|---|
| Price tier | Mid-range | Economy |
| Bugs caughtshare of known bugs | 68% (better) | 61% |
| False alarmsper clean PR | 1.0 (better) | 1.8 |
| Cost per reviewmeasured | $0.0862 | $0.0035 (better) |
| Cost per bug caught | $0.1166 | $0.0066 (better) |
| Exact linecatches on the expected lines | 94% (better) | 89% |
| Review timemean | 427s | 254s (better) |
| Typical review calllist price | $0.0287 | $0.0051 (better) |
| Input / 1M tokens | $0.75 | $0.15 (better) |
| Output / 1M tokens | $3.75 | $0.50 (better) |
| Context window | 1M | 1M |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gemini 3.8 Flash | 68% | 83% | 75% | 43% | 75% | 78% | 67% | 0% | 50% | 83% | 100% | 100% | 50% | 50% |
| GLM-5.3 Flash (Workers AI) | 61% | 57% | 31% | 45% | 88% | 30% | 67% | 89% | 33% | 78% | 67% | 67% | 100% | 67% |
Of the 42 known bugs both were scored on, both caught 27 and neither caught 3. Gemini 3.8 Flash caught 4 bugs that GLM-5.3 Flash (Workers AI) missed: 1 in C#, 1 in Go, 1 in PHP and 1 in TypeScript, most of them logic bugs. GLM-5.3 Flash (Workers AI) caught 8 bugs that Gemini 3.8 Flash missed: 3 in Kotlin, 2 in Java, 1 in C++, 1 in JavaScript and 1 in Rust.
On pull requests with no known bug, Gemini 3.8 Flash raised 1 false alarms per review and GLM-5.3 Flash (Workers AI) 1.8. A measured review cost $0.0862 on Gemini 3.8 Flash, 24× the cost of $0.0035 on GLM-5.3 Flash (Workers AI).
| Pull request | Language · kind | Gemini 3.8 Flash | GLM-5.3 Flash (Workers AI) |
|---|---|---|---|
| TanStack/queryfix(query-core): fix hydration bugs for already resolved promises | TypeScript · Logic | 1/1 | 0/4 |
| doctrine/ormFix collection filtering API for IN/NOT IN comparisons that require type conversions | PHP · Logic | 2/2 | 0/3 |
| dotnet/orleansfix(serialization): cap codec allocations | C# · Logic | 1/1 | 0/3 |
| go-chi/chifeat: middleware.ClientIP, a replacement for middleware.RealIP | Go · Security | 1/1 | 0/3 |
| ggml-org/llama.cpprpc : cache and reuse compute graphs | C++ · Security | 0/1 | 3/3 |
| jhy/jsoupStore cached child els in Attributes, not field | Java · Concurrency | 0/4 | 2/6 |
| kotest/kotestFix DataClassEq comparator | Kotlin · Logic | 0/1 | 2/3 |
| kotest/kotestRefactor eventually to ensure wall-clock time usage | Kotlin · Error handling | 0/1 | 3/3 |
| ktorio/ktorKTOR-9171 Redesign ByteReadChannel.readUTF8Line API | Kotlin · Logic | 0/1 | 4/4 |
| mockito/mockitoAdd core API to enable Kotlin singleton mocking | Java · API misuse | 0/1 | 1/4 |
| nodejs/undicifeat: add configurable maxPayloadSize for WebSocket | JavaScript · Security | 0/1 | 3/3 |
| nushell/nushellreorganize nushell configuration | Rust · Error handling | 0/1 | 2/4 |
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: Gemini 3.8 Flash and GLM-5.3 Flash (Workers AI).