DeepSeek V4 Pro (Workers AI) vs Gemini 4 Argon
DeepSeek V4 Pro (Workers AI) reads a 26.2K-token pull request for $0.0346, 34% less than Gemini 4 Argon ($0.0524). Both sit in the mid-range price tier, so the choice between them is about review quality more than budget. In the benchmark Gemini 4 Argon caught 28 percentage points more of the known defects than DeepSeek V4 Pro (Workers AI) (95% interval −41 pts to −16 pts, a − b).
Side by side
| Figure | DeepSeek V4 Pro (Workers AI) | Gemini 4 Argon |
|---|---|---|
| Price tier | Mid-range | Mid-range |
| Bugs caughtshare of known bugs | 54% | 82% (better) |
| False alarmsper clean PR | 2.9 | 1.1 (better) |
| Cost per reviewmeasured | $0.0643 | $0.0527 (better) |
| Cost per bug caught | $0.0872 | $0.0706 (better) |
| Exact linecatches on the expected lines | 89% (better) | 78% |
| Review timemean | 390s | 99s (better) |
| Typical review calllist price | $0.0442 (better) | $0.0766 |
| Input / 1M tokens | $1.32 (better) | $2.00 |
| Output / 1M tokens | $3.96 (better) | $10.00 |
| 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DeepSeek V4 Pro (Workers AI) | 54% | 79% | 25% | 49% | 54% | 59% | 17% | 30% | 69% | 72% | 67% | 75% | 38% | 33% |
| 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 31 and neither caught 3. DeepSeek V4 Pro (Workers AI) caught 3 bugs that Gemini 4 Argon missed: 1 in C, 1 in JavaScript and 1 in Rust. Gemini 4 Argon caught 5 bugs that DeepSeek V4 Pro (Workers AI) missed: 2 in JavaScript, 1 in C#, 1 in Go and 1 in Rust.
On pull requests with no known bug, DeepSeek V4 Pro (Workers AI) raised 2.9 false alarms per review and Gemini 4 Argon 1.1. A measured review cost $0.0643 on DeepSeek V4 Pro (Workers AI), 22% more than $0.0527 on Gemini 4 Argon.
| Pull request | Language · kind | DeepSeek V4 Pro (Workers AI) | Gemini 4 Argon |
|---|---|---|---|
| nushell/nushellreorganize nushell configuration | Rust · Error handling | 3/4 | 0/1 |
| nodejs/undicifeat: add configurable maxPayloadSize for WebSocket | JavaScript · Security | 2/4 | 0/1 |
| 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 | 1/3 | 0/1 |
| denoland/denoperf(libs/core): poll only ready handles and yield between I/O batches | Rust · Concurrency | 0/4 | 1/1 |
| dotnet/orleansfix(serialization): cap codec allocations | C# · Logic | 0/4 | 1/1 |
| go-chi/chifeat: middleware.ClientIP, a replacement for middleware.RealIP | Go · Security | 0/4 | 1/1 |
| pinojs/thread-streamrefactor: replace setTimeout with Atomics.waitAsync | JavaScript · Concurrency | 0/4 | 1/1 |
| sindresorhus/p-throttleAdd `weight` option | JavaScript · Logic | 0/4 | 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: DeepSeek V4 Pro (Workers AI) and Gemini 4 Argon.