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DeepSeek V4 Flash vs Qwen3.5 397B

Head-to-head comparison across 3benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.

DeepSeek V4 Flash

59

VS

Qwen3.5 397B

64

0 categoriesvs3 categories

Verified leaderboard positions: DeepSeek V4 Flash #23 · Qwen3.5 397B #14

Pick Qwen3.5 397B if you want the stronger benchmark profile. DeepSeek V4 Flash only becomes the better choice if you want the cheaper token bill or you need the larger 1M context window.

Category Radar

Head-to-Head by Category

Category Breakdown

Agentic

Qwen3.5 397B
49.1vs56.2

+7.1 difference

Coding

Qwen3.5 397B
57.1vs60.3

+3.2 difference

Knowledge

Qwen3.5 397B
45.2vs65.2

+20.0 difference

Operational Comparison

DeepSeek V4 Flash

Qwen3.5 397B

Price (per 1M tokens)

$0.14 / $0.28

$0.6 / $3.6

Speed

N/A

96 t/s

Latency (TTFT)

N/A

2.44s

Context Window

1M

128K

Quick Verdict

Pick Qwen3.5 397B if you want the stronger benchmark profile. DeepSeek V4 Flash only becomes the better choice if you want the cheaper token bill or you need the larger 1M context window.

Qwen3.5 397B is clearly ahead on the provisional aggregate, 64 to 59. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Qwen3.5 397B's sharpest advantage is in knowledge, where it averages 65.2 against 45.2. The single biggest benchmark swing on the page is HLE, 8.1% to 28.7%.

Qwen3.5 397B is also the more expensive model on tokens at $0.60 input / $3.60 output per 1M tokens, versus $0.14 input / $0.28 output per 1M tokens for DeepSeek V4 Flash. That is roughly 12.9x on output cost alone. DeepSeek V4 Flash gives you the larger context window at 1M, compared with 128K for Qwen3.5 397B.

Benchmark Deep Dive

Frequently Asked Questions (4)

Which is better, DeepSeek V4 Flash or Qwen3.5 397B?

Qwen3.5 397B is ahead on BenchLM's provisional leaderboard, 64 to 59. The biggest single separator in this matchup is HLE, where the scores are 8.1% and 28.7%.

Which is better for knowledge tasks, DeepSeek V4 Flash or Qwen3.5 397B?

Qwen3.5 397B has the edge for knowledge tasks in this comparison, averaging 65.2 versus 45.2. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, DeepSeek V4 Flash or Qwen3.5 397B?

Qwen3.5 397B has the edge for coding in this comparison, averaging 60.3 versus 57.1. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, DeepSeek V4 Flash or Qwen3.5 397B?

Qwen3.5 397B has the edge for agentic tasks in this comparison, averaging 56.2 versus 49.1. Inside this category, MCP Atlas is the benchmark that creates the most daylight between them.

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Last updated: April 24, 2026

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