Compare / head-to-head
DeepSeek V4 ProvsQwen3.5-Flash
DeepSeek V4 Pro leads 5 of 5 shared benchmarks. Qwen3.5-Flash is 4.1x cheaper per token. Both offer a 1M-token context window.
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
5 – 0
DeepSeek V4 Pro leads
Cheaper per token
Qwen3.5-Flash
4.1x cheaper, input + output
Larger context
Tie
both 1M tokens
Provider uptime (30d)
100% · —
DeepSeek · Qwen
DeepSeek V4 Pro
DeepSeek · released 2026-08-13
text
Qwen3.5-Flash
Qwen · released 2026-02-23
textvision
Quality
Benchmark matrix
5 shared · 6 only DeepSeek V4 Pro · 0 only Qwen3.5-Flash| Benchmark | DeepSeek V4 Pro | Qwen3.5-Flash | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 5 | ||||
| GPQA Diamond | 90.9% ↗epoch | 82.3% ↗epoch | +8.6 pt | DeepSeek V4 Pro |
| LMArena Elo | 1450.6 ↗ | 1397.7 ↗ | +52.9 | DeepSeek V4 Pro |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 45.3% ↗epoch | 9.5% ↗epoch | +35.8 pt | DeepSeek V4 Pro |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 96.7% ↗epoch | 84.4% ↗epoch | +12.3 pt | DeepSeek V4 Pro |
| SimpleQA Verified | 47% ↗epoch | 20.3% ↗epoch | +26.7 pt | DeepSeek V4 Pro |
| Only DeepSeek V4 Pro reports · 6 | ||||
| AIME 2026 | 96.7% ↗matharena ⚠ | not reported | — | — |
| DeepSWE v1.1 | 62.7% ↗ | not reported | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | 2.4% ↗epoch | not reported | — | — |
| Humanity's Last Exam (with tools) | 60% ↗ | not reported | — | — |
| SWE-bench Verified (Epoch AI run) | 77.6% ↗epoch | not reported | — | — |
| Terminal-Bench 2.1 | 87.9% ↗ | not reported | — | — |
| Only Qwen3.5-Flash reports · 0 | ||||
| Qwen3.5-Flash reports nothing DeepSeek V4 Pro does not. | ||||
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is DeepSeek V4 Pro minus Qwen3.5-Flash in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | DeepSeek V4 Pro | Qwen3.5-Flash | Edge |
|---|---|---|---|
| Context window | 1M tokens | 1M tokens | Tie |
| Max output | 384K tokens | — | — |
| Input price / 1M | $0.435 ↗ | $0.029 ↗ | Qwen3.5-Flash |
| Output price / 1M | $0.87 ↗ | $0.287 ↗ | Qwen3.5-Flash |
| Cached input / 1M | $0.004 ↗ | — | — |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $1.31 | $0.316 | Qwen3.5-Flash |
| Modalities | text | text · vision | Qwen3.5-Flash |
| Released | 2026-08-13 | 2026-02-23 | — |
| Cited benchmark scores | 11 | 5 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
DeepSeek V4 Pro vs …
Models sharing the most benchmarksMore matchups
Qwen3.5-Flash vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run DeepSeek V4 Pro and Qwen3.5-Flash on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.