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HEAD TO HEAD · UPDATED NOV 6, 2026
Gemini 3.8 Flash vs GPT-6 Astra
Google DeepMind against OpenAI, 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 | GPT-6 Astra | |
|---|---|---|
| Arena Elo | 1496 source ↗ | 1476 source ↗ |
| GPQA Diamond | 95.4% source ↗ | 96.0% source ↗ |
| $ per 1M in / out | $0.75 / $3.75 source ↗ | $10 / $50 source ↗ |
| Blended $ per 1M (3:1) | $1.50 source ↗ | $20.00 source ↗ |
| Context window | 1M source ↗ | 1.05M source ↗ |
| Output speed | 117 tok/s source ↗ | not published |
| Released | Sep 2, 2026 source ↗ | Sep 3, 2026 source ↗ |
| Open weights | No source ↗ | No source ↗ |
| Reasoning effort tiers | low · medium · high (default: medium) | low · medium · high · xhigh · max (default: not stated) |
| API effort control | thinking_config={"thinking_level": "low" | "medium" | "high"} source ↗ | reasoning={"effort": "low" | "medium" | "high" | "xhigh" | "max"} source ↗ |
| Additional benchmarks | DeepSWE v1.1: 73.7% source ↗ | DeepSWE v1.1: 74.1% source ↗ Terminal-Bench 4.0: 57.9% source ↗ AA Intelligence Index v5.0.1: 57 (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 ↗ | OpenAI's most capable model: 96.0% GPQA Diamond, 74.1% DeepSWE v1.1 and 57.9% Terminal-Bench 4.0 (OpenAI). 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, Gemini 3.8 Flash is about 13.3 times cheaper per token. For overall answer quality as rated by people in blind tests, Gemini 3.8 Flash leads clearly (1496 vs 1476 Arena Elo). On release timing, Google DeepMind is at day 24 of a typical ~32-day gap (MID-CYCLE), and OpenAI is at day 11 of a typical ~23-day gap (ADOPT NOW · FRESH RELEASE).
Key differences from the sourced numbers
- Gemini 3.8 Flash is the cheaper option: $1.50 vs $20.00 per 1M tokens at a 3:1 input-to-output mix (about 13.3 times less).
- Gemini 3.8 Flash scores 20 Elo points higher (1496 vs 1476) on the Arena text leaderboard, where people vote on blind side-by-side answers.
- On GPQA Diamond they are close (95.4% vs 96.0%).
- Gemini 3.8 Flash pricing note: Until Dec 31, 2026; $1.50 / $7.50 from Jan 1, 2027. No higher rate for long prompts.
- GPT-6 Astra pricing note: Prompts up to 272K tokens; $20 / $75 above 272K. Batch and Flex: $5 / $25.
Frequently asked questions
Is Gemini 3.8 Flash or GPT-6 Astra better?
Gemini 3.8 Flash is the cheaper option: $1.50 vs $20.00 per 1M tokens at a 3:1 input-to-output mix (about 13.3 times less). Gemini 3.8 Flash scores 20 Elo points higher (1496 vs 1476) on the Arena text leaderboard, where people vote on blind side-by-side answers. On GPQA Diamond they are close (95.4% vs 96.0%). Gemini 3.8 Flash pricing note: Until Dec 31, 2026; $1.50 / $7.50 from Jan 1, 2027. No higher rate for long prompts. GPT-6 Astra pricing note: Prompts up to 272K tokens; $20 / $75 above 272K. Batch and Flex: $5 / $25.
Which one should I use: Gemini 3.8 Flash or GPT-6 Astra?
For high-volume work where cost matters most, Gemini 3.8 Flash is about 13.3 times cheaper per token. For overall answer quality as rated by people in blind tests, Gemini 3.8 Flash leads clearly (1496 vs 1476 Arena Elo). On release timing, Google DeepMind is at day 24 of a typical ~32-day gap (MID-CYCLE), and OpenAI is at day 11 of a typical ~23-day gap (ADOPT NOW · FRESH RELEASE).
How much does Gemini 3.8 Flash cost compared with GPT-6 Astra?
Gemini 3.8 Flash lists at $0.75 / $3.75 per 1M input/output tokens ($1.50/1M blended at 3:1). GPT-6 Astra lists at $10 / $50 per 1M input/output tokens ($20.00/1M blended at 3:1).
Facts checked Nov 5, 2026 against official sources. Every number links to its source. Spotted an error? Email [email protected].