GPT-6.1 Terra vs DeepSeek V4.1 Flash
Official OpenAI and DeepSeek API prices and LMArena scores, checked 2026-11-04. Add up to 2 more models to compare 4.
DeepSeek V4.1 Flash costs less; GPT-6.1 Terra wins more LMArena tasks.
DeepSeek V4.1 Flash is 3.3x cheaper on input and 4.2x cheaper on output. GPT-6.1 Terra scores 27 points higher for agent tasks. Across 2 shared LMArena tasks, GPT-6.1 Terra leads 2 to 0. A medium month (20M input + 5M output tokens) costs $45 on GPT-6.1 Terra and $12 on DeepSeek V4.1 Flash.
- Pick GPT-6.1 Terra if you care most about agent tasks (+27) and coding (+3).
- Pick DeepSeek V4.1 Flash if you want the lower bill ($12 vs $45 for a medium month) or you reuse long prompts (cached input $0.006 vs $0.05).
Medium: 20M input + 5M output tokens a month at list price (short-context rate, no caching or batch discounts).
Marked side is better: lower for prices, higher for context and scores. Bars are scaled to the larger of the two.
| Spec | GPT-6.1 Terra | DeepSeek V4.1 Flash |
|---|---|---|
| Price per 1M tokens | ||
| Input | $1 | $0.30 |
| Cached input | $0.05 | $0.006 |
| Output | $5 | $1.20 |
| Blend 3:1 | $2 | $0.525 |
| Sample month, medium | $45 | $12 |
| Context | ||
| Context window | 1.05M tokens | 1M tokens |
| Quality (LMArena, out of 100) | ||
| Coding | 49/100 #11 of 50 | 46/100 #12 of 50 |
| Chat | Not ranked | 17/100 #18 of 51 |
| Creative writing | Not ranked | 0/100 #22 of 51 |
| Roleplay and characters | Not ranked | 0/100 #24 of 51 |
| Reasoning and math | Not ranked | 40/100 #14 of 51 |
| Vision | Not ranked | 14/100 #19 of 33 |
| Long documents | Not ranked | Not ranked |
| Cheap bulk and agents | 67/100 #7 of 37 | 40/100 #17 of 37 |
| Details | ||
| Provider | OpenAI | DeepSeek |
| API model id | gpt-6.1-terra | deepseek-flash |
| Notes | New Oct 26, 2026. Prompts up to 272K. Longer prompts cost $2 in, $7.50 out. | Peak rate. Off-peak is half price. |
| Sources | ||
| Last checked | 2026-11-04 | 2026-11-04 |
| Official pricing | OpenAI pricing | DeepSeek pricing |
Plans from data checked hourly against each vendor's official pricing page. Vendors state limits in different units, so we quote them as published. Team and enterprise plans are per seat.
API prices in USD per 1M tokens from each provider's official pricing page. Blend 3:1 = (3 x input + output) / 4. Sample month = stated input and output tokens at the list price, no caching. Quality: relative score out of 100 on each LMArena leaderboard (100 = top model we price on that board, n/a = not ranked there), data licensed CC BY 4.0. See how we pick.
Where each one ranks on LMArena
Relative score out of 100 on each leaderboard (100 = the top model we price there), with the rank among the models from our API price table that appear on that board.
- Coding (Code Arena): GPT-6.1 Terra #11 of 50 (49/100), DeepSeek V4.1 Flash #12 of 50 (46/100)
- Chat (Text Arena): GPT-6.1 Terra not ranked, DeepSeek V4.1 Flash #18 of 51 (17/100)
- Creative writing (Text Arena creative writing): GPT-6.1 Terra not ranked, DeepSeek V4.1 Flash #22 of 51 (0/100)
- Roleplay and characters (Text Arena multi-turn): GPT-6.1 Terra not ranked, DeepSeek V4.1 Flash #24 of 51 (0/100)
- Reasoning and math (Text Arena math): GPT-6.1 Terra not ranked, DeepSeek V4.1 Flash #14 of 51 (40/100)
- Vision (Vision Arena): GPT-6.1 Terra not ranked, DeepSeek V4.1 Flash #19 of 33 (14/100)
- Long documents (Document Arena): GPT-6.1 Terra not ranked, DeepSeek V4.1 Flash not ranked
- Cheap bulk and agents (Agent Arena): GPT-6.1 Terra #7 of 37 (67/100), DeepSeek V4.1 Flash #17 of 37 (40/100)
Pricing details from the official pages
GPT-6.1 Terra lists $1 input, $5 output, $0.05 cached input per 1M tokens on OpenAI pricing. DeepSeek V4.1 Flash lists $0.30 input, $1.20 output, $0.006 cached input per 1M tokens on DeepSeek pricing. Prices checked 2026-11-04.
- GPT-6.1 Terra: New Oct 26, 2026. Prompts up to 272K. Longer prompts cost $2 in, $7.50 out.
- DeepSeek V4.1 Flash: Peak rate. Off-peak is half price.
Sample monthly bill at list price, no caching: Light (2M input + 0.5M output tokens): $4.50 vs $1.20. Medium (20M input + 5M output tokens): $45 vs $12. Heavy (200M input + 50M output tokens): $450 vs $120.
FAQ
Is GPT-6.1 Terra cheaper than DeepSeek V4.1 Flash?
GPT-6.1 Terra costs $1 input and $5 output per 1M tokens; DeepSeek V4.1 Flash costs $0.30 and $1.20. For a medium month (20M input + 5M output tokens) DeepSeek V4.1 Flash is cheaper: $12 vs $45.
Which is better for coding, GPT-6.1 Terra or DeepSeek V4.1 Flash?
On LMArena's Code Arena GPT-6.1 Terra scores 49/100 (#11 of 50) and DeepSeek V4.1 Flash 46/100 (#12 of 50), so GPT-6.1 Terra is ahead by 3 points.
Which has the bigger context window?
GPT-6.1 Terra: 1.05M tokens. DeepSeek V4.1 Flash: 1M tokens. Long prompts can cost more; see the pricing notes above.
How much do GPT-6.1 Terra and DeepSeek V4.1 Flash cost per month?
Light (2M input + 0.5M output tokens): $4.50 vs $1.20. Medium (20M input + 5M output tokens): $45 vs $12. Heavy (200M input + 50M output tokens): $450 vs $120. Pick your own token counts in the plan vs API calculator.
Where do these numbers come from?
Prices come from each provider's official pricing page, checked daily. Quality is the relative score on the LMArena leaderboard dataset, licensed CC BY 4.0. Where a model is not ranked we show n/a.
Sources
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