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HEAD TO HEAD · UPDATED NOV 6, 2026
Gemini 3.8 Flash vs DeepSeek V4-Pro
Google DeepMind against DeepSeek, on sourced numbers only. Green marks the higher (or cheaper) value on each row; the text below only calls a lead when the gap is bigger than measurement noise.
| Gemini 3.8 Flash | DeepSeek V4-Pro | |
|---|---|---|
| Arena Elo | 1496 source ↗ | 1465 source ↗ |
| GPQA Diamond | 95.4% source ↗ | 92.4% source ↗ |
| $ per 1M in / out | $0.75 / $3.75 source ↗ | $0.66 / $1.98 source ↗ |
| Blended $ per 1M (3:1) | $1.50 source ↗ | $0.99 source ↗ |
| Context window | 1M source ↗ | 1M source ↗ |
| Output speed | 117 tok/s source ↗ | not published |
| Released | Sep 2, 2026 source ↗ | Aug 13, 2026 source ↗ |
| Open weights | No source ↗ | Yes source ↗ |
| Reasoning effort tiers | low · medium · high (default: medium) | low · high · max (default: high) |
| API effort control | thinking_config={"thinking_level": "low" | "medium" | "high"} source ↗ | thinking={"type": "enabled" | "disabled"}, reasoning_effort="low" | "high" | "max" (medium and xhigh map to high) source ↗ |
| Additional benchmarks | DeepSWE v1.1: 73.7% source ↗ | SWE-bench Verified: 80.6% (April V4 preview card, Max) source ↗ |
| Best for (workload) | 95.4% on GPQA Diamond (Epoch AI) and 117 tok/s output (Artificial Analysis) at a Flash-tier price. source ↗ | Higher GPQA Diamond than V4.1-Flash (92.4% vs 90.9%, DeepSeek); MIT open weights. source ↗ |
Arena Elo from the arena.ai text leaderboard as of Oct 27, 2026 source ↗. Speed measured by Artificial Analysis and varies by provider.
Which one should I use?
For high-volume work where cost matters most, DeepSeek V4-Pro is about 1.5 times cheaper per token. For overall answer quality as rated by people in blind tests, Gemini 3.8 Flash leads clearly (1496 vs 1465 Arena Elo). For hard science and analysis questions, Gemini 3.8 Flash scores higher on GPQA Diamond (95.4% vs 92.4%). If you need to self-host or fine-tune, only DeepSeek V4-Pro has open weights. On release timing, Google DeepMind is at day 24 of a typical ~32-day gap (MID-CYCLE), and DeepSeek is at day 20 of a typical ~32-day gap (MID-CYCLE).
Key differences from the sourced numbers
- DeepSeek V4-Pro is the cheaper option: $0.99 vs $1.50 per 1M tokens at a 3:1 input-to-output mix (about 1.5 times less).
- Gemini 3.8 Flash scores 31 Elo points higher (1496 vs 1465) on the Arena text leaderboard, where people vote on blind side-by-side answers.
- On GPQA Diamond, graduate-level science questions, Gemini 3.8 Flash leads 95.4% to 92.4%.
- Gemini 3.8 Flash pricing note: Until Dec 31, 2026; $1.50 / $7.50 from Jan 1, 2027. No higher rate for long prompts.
- DeepSeek V4-Pro pricing note: Off-peak price (cache hit $0.022 / 1M). Peak hours (01:00 to 04:00 and 06:00 to 10:00 UTC, weekdays): $1.32 / $3.96 (cache hit $0.044 / 1M). API continues until V4.1-Pro launches.
Frequently asked questions
Is Gemini 3.8 Flash or DeepSeek V4-Pro better?
DeepSeek V4-Pro is the cheaper option: $0.99 vs $1.50 per 1M tokens at a 3:1 input-to-output mix (about 1.5 times less). Gemini 3.8 Flash scores 31 Elo points higher (1496 vs 1465) on the Arena text leaderboard, where people vote on blind side-by-side answers. On GPQA Diamond, graduate-level science questions, Gemini 3.8 Flash leads 95.4% to 92.4%. Gemini 3.8 Flash pricing note: Until Dec 31, 2026; $1.50 / $7.50 from Jan 1, 2027. No higher rate for long prompts. DeepSeek V4-Pro pricing note: Off-peak price (cache hit $0.022 / 1M). Peak hours (01:00 to 04:00 and 06:00 to 10:00 UTC, weekdays): $1.32 / $3.96 (cache hit $0.044 / 1M). API continues until V4.1-Pro launches.
Which one should I use: Gemini 3.8 Flash or DeepSeek V4-Pro?
For high-volume work where cost matters most, DeepSeek V4-Pro is about 1.5 times cheaper per token. For overall answer quality as rated by people in blind tests, Gemini 3.8 Flash leads clearly (1496 vs 1465 Arena Elo). For hard science and analysis questions, Gemini 3.8 Flash scores higher on GPQA Diamond (95.4% vs 92.4%). If you need to self-host or fine-tune, only DeepSeek V4-Pro has open weights. On release timing, Google DeepMind is at day 24 of a typical ~32-day gap (MID-CYCLE), and DeepSeek is at day 20 of a typical ~32-day gap (MID-CYCLE).
How much does Gemini 3.8 Flash cost compared with DeepSeek V4-Pro?
Gemini 3.8 Flash lists at $0.75 / $3.75 per 1M input/output tokens ($1.50/1M blended at 3:1). DeepSeek V4-Pro lists at $0.66 / $1.98 per 1M input/output tokens ($0.99/1M blended at 3:1).
Facts checked Nov 5, 2026 against official sources. Every number links to its source. Spotted an error? Email [email protected].