Seed 2.1 Turbo vs DeepSeek V4.1 Flash
Official ByteDance Seed and DeepSeek API prices and LMArena scores, checked 2026-10-30. Add up to 2 more models to compare 4.
DeepSeek V4.1 Flash costs less; quality is n/a.
DeepSeek V4.1 Flash is 1.7x cheaper on input and 2.1x cheaper on output. LMArena has no task both models are ranked on, so quality is n/a here. DeepSeek V4.1 Flash has the longer context window (1M vs 256K tokens). A medium month (20M input + 5M output tokens) costs $22.50 on Seed 2.1 Turbo and $12 on DeepSeek V4.1 Flash.
- Pick Seed 2.1 Turbo if nothing here clearly favors it (no lower bill, bigger context, cheaper cache or LMArena lead of 3+ points over DeepSeek V4.1 Flash).
- Pick DeepSeek V4.1 Flash if you want the lower bill ($12 vs $22.50 for a medium month), you need the 1M context window or you reuse long prompts (cached input $0.006 vs $0.10).
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 | Seed 2.1 Turbo | DeepSeek V4.1 Flash |
|---|---|---|
| Price per 1M tokens | ||
| Input | $0.50 | $0.30 |
| Cached input | $0.10 | $0.006 |
| Output | $2.50 | $1.20 |
| Blend 3:1 | $1 | $0.525 |
| Sample month, medium | $22.50 | $12 |
| Context | ||
| Context window | 256K tokens | 1M tokens |
| Quality (LMArena, out of 100) | ||
| Coding | Not ranked | 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 | Not ranked | 39/100 #14 of 37 |
| Details | ||
| Provider | ByteDance Seed | DeepSeek |
| API model id | seed-2.1-turbo | deepseek-flash |
| Notes | BytePlus ModelArk price. Prompts up to 256K. | Peak rate. Off-peak is half price. |
| Sources | ||
| Last checked | 2026-10-30 | 2026-10-30 |
| Official pricing | ByteDance Seed 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): Seed 2.1 Turbo not ranked, DeepSeek V4.1 Flash #12 of 50 (46/100)
- Chat (Text Arena): Seed 2.1 Turbo not ranked, DeepSeek V4.1 Flash #18 of 51 (17/100)
- Creative writing (Text Arena creative writing): Seed 2.1 Turbo not ranked, DeepSeek V4.1 Flash #22 of 51 (0/100)
- Roleplay and characters (Text Arena multi-turn): Seed 2.1 Turbo not ranked, DeepSeek V4.1 Flash #24 of 51 (0/100)
- Reasoning and math (Text Arena math): Seed 2.1 Turbo not ranked, DeepSeek V4.1 Flash #14 of 51 (40/100)
- Vision (Vision Arena): Seed 2.1 Turbo not ranked, DeepSeek V4.1 Flash #19 of 33 (14/100)
- Long documents (Document Arena): Seed 2.1 Turbo not ranked, DeepSeek V4.1 Flash not ranked
- Cheap bulk and agents (Agent Arena): Seed 2.1 Turbo not ranked, DeepSeek V4.1 Flash #14 of 37 (39/100)
Pricing details from the official pages
Seed 2.1 Turbo lists $0.50 input, $2.50 output, $0.10 cached input per 1M tokens on ByteDance Seed pricing. DeepSeek V4.1 Flash lists $0.30 input, $1.20 output, $0.006 cached input per 1M tokens on DeepSeek pricing. Prices checked 2026-10-30.
- Seed 2.1 Turbo: BytePlus ModelArk price. Prompts up to 256K.
- 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): $2.25 vs $1.20. Medium (20M input + 5M output tokens): $22.50 vs $12. Heavy (200M input + 50M output tokens): $225 vs $120.
FAQ
Is Seed 2.1 Turbo cheaper than DeepSeek V4.1 Flash?
Seed 2.1 Turbo costs $0.50 input and $2.50 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 $22.50.
Which is better for coding, Seed 2.1 Turbo or DeepSeek V4.1 Flash?
Code Arena score: Seed 2.1 Turbo n/a (not ranked), DeepSeek V4.1 Flash 46/100. We do not guess missing scores.
Which has the bigger context window?
Seed 2.1 Turbo: 256K tokens. DeepSeek V4.1 Flash: 1M tokens.
How much do Seed 2.1 Turbo and DeepSeek V4.1 Flash cost per month?
Light (2M input + 0.5M output tokens): $2.25 vs $1.20. Medium (20M input + 5M output tokens): $22.50 vs $12. Heavy (200M input + 50M output tokens): $225 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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