Home / Compare / DeepSeek V4 Flash vs Qwen3.5 397B A17B DeepSeek V4 Flash vs Qwen3.5 397B A17B DeepSeek V4 Flash grades higher overall (72.1 against 65.4). DeepSeek V4 Flash costs 90% less for the same work.
Model AClaude Fable 5 Claude Haiku 4.5 Claude Opus 4.7 Claude Opus 4.8 Claude Opus 5 Claude Opus 5.5 Claude Sonnet 4.6 Claude Sonnet 5 Claude Sonnet 5.5 DeepSeek R1 0528 DeepSeek V3 DeepSeek V3.1 DeepSeek V3.2 DeepSeek V4 Flash DeepSeek V4 Flash 0731 DeepSeek V4 Pro 0813 DeepSeek V4.1 Flash Gemini 2.5 Flash Gemini 2.5 Pro Gemini 3.1 Flash Lite Gemini 3.1 Pro Gemini 3.5 Flash Gemini 3.7 Flash Gemma 3 12B IT Gemma 3 27B IT Gemma 3 4B IT Gemma 4 26B A4B IT Gemma 4 31B IT GLM 4.6 GLM 4.7 GLM 5.2 GLM 5.3 GLM 5.3 Flash GPT OSS 120B GPT OSS 20B Granite 4.2 8B Hy4 Preview Inkling Small Kimi K2.6 Kimi K3 Ling 3.1 Flash Llama 3.3 70B Instruct Turbo Llama 4 Scout 17B 16E Instruct Meta Llama 3.1 70B Instruct Turbo Meta Llama 3.1 8B Instruct Turbo MiMo V2.6 Flash MiMo V2.6 Pro MiniMax M3 Mistral Small 24B Instruct 2501 Mistral Small 3.2 24B Instruct 2506 Muse Glimmer 30B NVIDIA Nemotron 3 Super 120B A12B NVIDIA Nemotron 3 Ultra 550B A55B NVIDIA Nemotron 3.5 Lightning Phi 4 Qwen2.5 72B Instruct Qwen3 235B A22B Instruct 2507 Qwen3 30B A3B Qwen3 32B Qwen3 Coder 480B A35B Instruct Turbo Qwen3 Next 80B A3B Instruct Qwen3 VL 235B A22B Instruct Qwen3.5 27B Qwen3.5 35B A3B Qwen3.5 397B A17B Qwen3.5 9B Qwen3.6 27B Qwen3.6 35B A3B Qwen3.7 Max Qwen3.8 27B Qwen3.8 Flash Qwen3.8 Max Seed 2.0 Pro Step 5 Preview DeepSeek V4 Flash
by DeepSeek · #27 of 67 overall
Coming soon · price at launch
Context 1M
Input / 1M $0.090
Output / 1M $0.18 Model BClaude Fable 5 Claude Haiku 4.5 Claude Opus 4.7 Claude Opus 4.8 Claude Opus 5 Claude Opus 5.5 Claude Sonnet 4.6 Claude Sonnet 5 Claude Sonnet 5.5 DeepSeek R1 0528 DeepSeek V3 DeepSeek V3.1 DeepSeek V3.2 DeepSeek V4 Flash DeepSeek V4 Flash 0731 DeepSeek V4 Pro 0813 DeepSeek V4.1 Flash Gemini 2.5 Flash Gemini 2.5 Pro Gemini 3.1 Flash Lite Gemini 3.1 Pro Gemini 3.5 Flash Gemini 3.7 Flash Gemma 3 12B IT Gemma 3 27B IT Gemma 3 4B IT Gemma 4 26B A4B IT Gemma 4 31B IT GLM 4.6 GLM 4.7 GLM 5.2 GLM 5.3 GLM 5.3 Flash GPT OSS 120B GPT OSS 20B Granite 4.2 8B Hy4 Preview Inkling Small Kimi K2.6 Kimi K3 Ling 3.1 Flash Llama 3.3 70B Instruct Turbo Llama 4 Scout 17B 16E Instruct Meta Llama 3.1 70B Instruct Turbo Meta Llama 3.1 8B Instruct Turbo MiMo V2.6 Flash MiMo V2.6 Pro MiniMax M3 Mistral Small 24B Instruct 2501 Mistral Small 3.2 24B Instruct 2506 Muse Glimmer 30B NVIDIA Nemotron 3 Super 120B A12B NVIDIA Nemotron 3 Ultra 550B A55B NVIDIA Nemotron 3.5 Lightning Phi 4 Qwen2.5 72B Instruct Qwen3 235B A22B Instruct 2507 Qwen3 30B A3B Qwen3 32B Qwen3 Coder 480B A35B Instruct Turbo Qwen3 Next 80B A3B Instruct Qwen3 VL 235B A22B Instruct Qwen3.5 27B Qwen3.5 35B A3B Qwen3.5 397B A17B Qwen3.5 9B Qwen3.6 27B Qwen3.6 35B A3B Qwen3.7 Max Qwen3.8 27B Qwen3.8 Flash Qwen3.8 Max Seed 2.0 Pro Step 5 Preview Qwen3.5 397B A17B
by Qwen · #35 of 67 overall
Coming soon · price at launch
Context 256K
Input / 1M $0.45
Output / 1M $3.00 Better overall
DeepSeek V4 Flash
Grade 72.1 vs 65.4
Cheaper
DeepSeek V4 Flash
90% less, $0.11 vs $1.09 blended
Larger context
DeepSeek V4 Flash
1M vs 256K tokens
SWE-bench Verified
DeepSeek V4 Flash
79% vs 76.4%
Head to head Public benchmarks. Longer is better; each value links to its source.
LMArena Text Elo-style rating · LMArena (CC BY 4.0) · Oct 15, 2026 SWE-Bench Pro % of tasks resolved · Scale AI SWE-Bench Pro · Apr 22, 2026 · reference Qwen3.5 397B A17B Qwen3.5 397B A17B: —
LiveCodeBench pass@1, % · LiveCodeBench · Apr 22, 2026 · reference
DeepSeek V4 Flash $25.20 /month
Qwen3.5 397B A17B $210 /month
DeepSeek V4 Flash saves you $185 a month at this usage, $2,218 a year.
At a glance Attribute DeepSeek V4 Flash Qwen3.5 397B A17B Made by DeepSeek Qwen Availability Coming soon Coming soon Overall grade Excellent · 72.1 Strong · 65.4 Overall rank #27 of 67 #35 of 67 Input price $0.090 per 1M $0.45 per 1M Output price $0.18 per 1M $3.00 per 1M Context window 1,048,576 tokens 262,144 tokens Reasoning levels No Yes Reads images No Yes Model ID deepseek-v4-flash qwen3.5-397b-a17b
Try both with one key Same endpoint, same key, both hosted in the USA. Change one word to switch models, in Claude Code, Cursor, Cline or your own code.
Get your API key # Ask either model the same thing
curl https://fullsendai.com/v1/chat/completions \
-H "Authorization: Bearer $FULLSEND_API_KEY " \
-d '{"model": "deepseek-v4-flash", "messages": [...]}'
# …then swap one word
-d '{"model": "qwen3.5-397b-a17b", "messages": [...]}' Questions Is DeepSeek V4 Flash or Qwen3.5 397B A17B better? DeepSeek V4 Flash grades 72.1 against 65.4 for Qwen3.5 397B A17B, from public benchmarks.
Which is cheaper, DeepSeek V4 Flash or Qwen3.5 397B A17B? DeepSeek V4 Flash: $0.090 in and $0.18 out per million tokens, against $0.45 and $3.00 through FullsendAI.
Which has the larger context window? DeepSeek V4 Flash, with 1,048,576 tokens.
Can I use both with one API key? Yes, once they launch: both are coming soon, at the prices shown, and both will use the same FullsendAI key.
Scores: LMArena (CC BY 4.0), SWE-bench, Scale AI SWE-Bench Pro, Terminal-Bench, LiveCodeBench, and model makers’ published results where marked v. Prices are FullsendAI’s, per million tokens. Data as of Oct 28, 2026.
