GPT-6 Astra vs DeepSeek-V4 Pro

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

GPT-6 Astra
OpenAI
AI Mastery Index96.7
LMSYS Arena1496
Technical (MMLU-Pro)95.8%
Cost per 1M Tokens$10
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?

GPT-6 Astra leads on the composite index by 4.9 points (96.7 vs 91.8).

Cost is the sharper difference: GPT-6 Astra is 7.6x the input price of DeepSeek-V4 Pro ($10 against $1.32 per 1M), so at volume the choice is usually decided by budget rather than benchmarks.

Pick GPT-6 Astra when

  • Higher composite index — 96.7 against 91.8, a gap of 4.9 points.
  • Ahead on Arena Elo by 47 points (1496 vs 1449), which is outside the board's published confidence intervals.
  • Stronger on MMLU-Pro: 95.8% against 91.8%.

Pick DeepSeek-V4 Pro when

  • Cheaper input tokens — $1.32 against $10 per 1M, so GPT-6 Astra costs 7.6x as much to feed.
  • Better value per point of measured capability: $0.014 per index point against $0.103.

Value per point of measured capability, at list input pricing: DeepSeek-V4 Pro $0.014 · GPT-6 Astra $0.103 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 OpenAI and DeepSeek