API cost decision in 10 seconds

NewSeed 2.1 Turbo vs GPT-5.6 Terra Pro (batch)

Pick Seed 2.1 Turbo for lower cost; pick GPT-5.6 Terra Pro (batch) only if the larger context window matters more.

Page updated:  Data confirmed:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Seed 2.1 Turbo for lower cost; pick GPT-5.6 Terra Pro (batch) only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Seed 2.1 Turbo is estimated at $1.75 vs $4 for GPT-5.6 Terra Pro (batch), saving $2.25 (56.2% lower).

Cost-first pickSeed 2.1 Turbo
Context-first pickGPT-5.6 Terra Pro (batch)
Sample savings$2.2556.2%
10x traffic gap$22.5

GPT-5.6 Terra Pro (batch) has more context, but Seed 2.1 Turbo saves $2.25 on the standard workload. At 10x that traffic, the same price gap is about $22.5. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Seed 2.1 Turbo stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickSeed 2.1 TurboGPT-5.6 Terra Pro (batch)
Input-heavy / RAG5M input + 500K outputSeed 2.1 Turbo$3.75$8
Balanced workload1M input + 1M outputSeed 2.1 Turbo$3$7
Output-heavy chatbot1M input + 5M outputSeed 2.1 Turbo$13$31
Cheaper input Seed 2.1 Turbo $0.5 vs $1 / 1M

Seed 2.1 Turbo is $0.5 cheaper per 1M input tokens (50% lower; 2x difference).

Cheaper output Seed 2.1 Turbo $2.5 vs $6 / 1M

Seed 2.1 Turbo is $3.5 cheaper per 1M output tokens (58.3% lower; 2.4x difference).

Larger context GPT-5.6 Terra Pro (batch) 262.14K vs 1.05M

GPT-5.6 Terra Pro (batch) has 787.86K more context (4.01x larger).

Sample workload Seed 2.1 Turbo $1.75 vs $4

Seed 2.1 Turbo is $2.25 cheaper on the standard workload (56.2% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
Seed 2.1 Turbo Calculating… Estimated API cost
GPT-5.6 Terra Pro (batch) Calculating… Estimated API cost
Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

Seed 2.1 Turbo has the lower input price; Seed 2.1 Turbo has the lower output price; GPT-5.6 Terra Pro (batch) offers the larger context window. For the 1M input plus 500K output sample, Seed 2.1 Turbo is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $1.75 for Seed 2.1 Turbo and $4 for GPT-5.6 Terra Pro (batch).

Best Fit

Choose Seed 2.1 Turbo when you care most about lower input-token price, and lower output-token price.

Choose GPT-5.6 Terra Pro (batch) when you care most about larger context window.

Decision Notes
  • On the standard 1M input plus 500K output workload, Seed 2.1 Turbo is estimated at $1.75 vs $4 for GPT-5.6 Terra Pro (batch), saving $2.25 (56.2% lower).
  • Seed 2.1 Turbo is $2.25 cheaper on the standard workload (56.2% lower).
  • Seed 2.1 Turbo is $0.5 cheaper per 1M input tokens (50% lower; 2x difference).
  • Seed 2.1 Turbo is $3.5 cheaper per 1M output tokens (58.3% lower; 2.4x difference).
  • GPT-5.6 Terra Pro (batch) has 787.86K more context (4.01x larger).
Head-to-Head Specs
FeatureNewSeed 2.1 Turbo
(ByteDance Seed)		GPT-5.6 Terra Pro (batch)
(OpenAI)
Input Price
prompt tokens per 1M		$0.5$1
Completion Price
per 1M tokens		$2.5$6
Sample Workload Cost
1M input + 500K output		$1.75$4
Context Window262.14K1.05M
Release Date

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionSeed 2.1 TurboOn the standard 1M input plus 500K output workload, Seed 2.1 Turbo is estimated at $1.75 vs $4 for GPT-5.6 Terra Pro (batch), saving $2.25 (56.2% lower).
High-volume input processingSeed 2.1 TurboLower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsSeed 2.1 TurboLower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workGPT-5.6 Terra Pro (batch)A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • Seed 1.6 Flash can replace Seed 2.1 Turbo when lower sample workload cost matters most: $0.22.
  • Seed-2.0-Mini can replace Seed 2.1 Turbo when lower sample workload cost matters most: $0.3.
  • Seed-2.0-Lite can replace Seed 2.1 Turbo when lower sample workload cost matters most: $1.25.
  • Seed 1.6 can replace Seed 2.1 Turbo when lower sample workload cost matters most: $1.25.

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

Open cheapest models

Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

Open provider hubs

ByteDance Seed catalog

Review all tracked ByteDance Seed models before deciding whether this matchup is the right shortlist.

Open ByteDance Seed models

OpenAI catalog

Check other OpenAI models with comparable pricing, context, or release timing.

Open OpenAI models
Seed 2.1 Turbo

Seed 2.1 Turbo is a multimodal model from ByteDance Seed for coding and long-horizon agent workflows. It is suited for end-to-end software delivery, multi-step task execution, and understanding visual and...

GPT-5.6 Terra Pro (batch)

GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode