Head to head
DeepSeek V4 Flash 0731vsQwen3.5-9B
For tasks, about a month.
Verdict · measured basis
DeepSeek V4 Flash 0731 costs $0.0002 per solved task against
Qwen3.5-9B at $0.0038 — ▼ 22x cheaper.
Over 200 tasks that is $0.73 a month.
On output token price alone DeepSeek V4 Flash 0731 looks 1.3x cheaper. The ranking holds, but the margin changes.
Verified pricing, pass rate and cost per solved task for DeepSeek V4 Flash 0731 and Qwen3.5-9B| Figure | DeepSeek V4 Flash 0731 | Qwen3.5-9B |
|---|
| Input $/Mtok | $0.06 | $0.1 |
|---|
| Output $/Mtok | $0.12 | $0.15 |
|---|
| Cached input $/Mtok | $0.012 | $0.1 |
|---|
| Pass rate | 89% | 28% |
|---|
| Cost per solved task | $0.0002measured | $0.0038measured |
|---|
| Cost per month | $0.04 | $0.77 |
|---|
Cost per month against tasks per month · drag the marker
Solid measured · dashed modeled · dotted stale. The gap is the verdict.
Solvency Bench (solvency.dev) — first-party measurement · verified 2026-08-26 · prices from each provider's pricing page; measured rows ignore the tier · Methodology · All models at these settings