Gemini 3.8 Flash vs DeepSeek-V4 Pro

Head-to-head technical comparison of intelligence, capabilities, and API pricing.

Gemini 3.8 Flash
Google
AI Mastery Index93.5
LMSYS Arena1494
Technical (MMLU-Pro)93.2%
Cost per 1M Tokens$0.75
DeepSeek-V4 Pro
DeepSeek
AI Mastery Index91.8
LMSYS Arena1449
Technical (MMLU-Pro)91.8%
Cost per 1M Tokens$1.32

Which should you use?

Gemini 3.8 Flash leads on the composite index by 1.7 points (93.5 vs 91.8).

Cost is the sharper difference: DeepSeek-V4 Pro is 1.8x the input price of Gemini 3.8 Flash ($1.32 against $0.75 per 1M), so at volume the choice is usually decided by budget rather than benchmarks.

Pick Gemini 3.8 Flash when

  • Higher composite index — 93.5 against 91.8, a gap of 1.7 points.
  • Ahead on Arena Elo by 45 points (1494 vs 1449), which is outside the board's published confidence intervals.
  • Stronger on MMLU-Pro: 93.2% against 91.8%.
  • Cheaper input tokens — $0.75 against $1.32 per 1M, so DeepSeek-V4 Pro costs 1.8x as much to feed.
  • Better value per point of measured capability: $0.008 per index point against $0.014.

Pick DeepSeek-V4 Pro when

On these measures DeepSeek-V4 Pro does not lead Gemini 3.8 Flash anywhere, so pick it only for reasons outside this table — an existing integration, a region, or a contract.

Value per point of measured capability, at list input pricing: Gemini 3.8 Flash $0.008 · DeepSeek-V4 Pro $0.014 per index point. Run your own token mix through the token cost calculator — a comparison at list price ignores caching and batch discounts, which move real bills more than this gap does.

Our reporting on Google and DeepSeek