Seed 1.6 Flash is $0.18 cheaper per 1M input tokens (71.2% lower; 3.47x difference).
API cost decision in 10 seconds
Qwen3.5 Plus 2026-02-15 vs Seed 1.6 Flash
Pick Seed 1.6 Flash for lower cost; pick Qwen3.5 Plus 2026-02-15 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 1.6 Flash for lower cost; pick Qwen3.5 Plus 2026-02-15 only if the larger context window matters more.
On the standard 1M input plus 500K output workload, Seed 1.6 Flash is estimated at $0.22 vs $1.04 for Qwen3.5 Plus 2026-02-15, saving $0.82 (78.4% lower).
Cost-first pickSeed 1.6 Flash
Context-first pickQwen3.5 Plus 2026-02-15
Sample savings$0.8278.4%
10x traffic gap$8.15
Qwen3.5 Plus 2026-02-15 has more context, but Seed 1.6 Flash saves $0.82 on the standard workload. At 10x that traffic, the same price gap is about $8.15. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
Seed 1.6 Flash stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | Qwen3.5 Plus 2026-02-15 | Seed 1.6 Flash |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | Seed 1.6 Flash | $2.08 | $0.53 |
| Balanced workload | 1M input + 1M output | Seed 1.6 Flash | $1.82 | $0.38 |
| Output-heavy chatbot | 1M input + 5M output | Seed 1.6 Flash | $8.06 | $1.57 |
Seed 1.6 Flash is $1.26 cheaper per 1M output tokens (80.8% lower; 5.2x difference).
Qwen3.5 Plus 2026-02-15 has 737.86K more context (3.81x larger).
Seed 1.6 Flash is $0.82 cheaper on the standard workload (78.4% lower).
Estimate your workload cost
Your Workload Cost
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
Seed 1.6 Flash has the lower input price; Seed 1.6 Flash has the lower output price; Qwen3.5 Plus 2026-02-15 offers the larger context window. For the 1M input plus 500K output sample, Seed 1.6 Flash is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $1.04 for Qwen3.5 Plus 2026-02-15 and $0.22 for Seed 1.6 Flash.
Choose Qwen3.5 Plus 2026-02-15 when you care most about larger context window.
Choose Seed 1.6 Flash when you care most about lower input-token price, and lower output-token price.
- On the standard 1M input plus 500K output workload, Seed 1.6 Flash is estimated at $0.22 vs $1.04 for Qwen3.5 Plus 2026-02-15, saving $0.82 (78.4% lower).
- Seed 1.6 Flash is $0.82 cheaper on the standard workload (78.4% lower).
- Seed 1.6 Flash is $0.18 cheaper per 1M input tokens (71.2% lower; 3.47x difference).
- Seed 1.6 Flash is $1.26 cheaper per 1M output tokens (80.8% lower; 5.2x difference).
- Qwen3.5 Plus 2026-02-15 has 737.86K more context (3.81x larger).
| Feature | Qwen3.5 Plus 2026-02-15 (Qwen) | Seed 1.6 Flash (ByteDance Seed) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.26 | $0.075 |
| Completion Price per 1M tokens | $1.56 | $0.3 |
| Sample Workload Cost 1M input + 500K output | $1.04 | $0.22 |
| Context Window | 1M | 262.14K |
| Release Date |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | Seed 1.6 Flash | On the standard 1M input plus 500K output workload, Seed 1.6 Flash is estimated at $0.22 vs $1.04 for Qwen3.5 Plus 2026-02-15, saving $0.82 (78.4% lower). |
| High-volume input processing | Seed 1.6 Flash | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | Seed 1.6 Flash | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | Qwen3.5 Plus 2026-02-15 | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- Qwen3 Next 80B A3B Instruct (free) can replace Qwen3.5 Plus 2026-02-15 when lower sample workload cost matters most: $0.
- Qwen3 Coder 480B A35B (free) can replace Qwen3.5 Plus 2026-02-15 when lower sample workload cost matters most: $0.
- Qwen2.5 7B Instruct can replace Qwen3.5 Plus 2026-02-15 when lower sample workload cost matters most: $0.09.
- Qwen3.5-9B can replace Qwen3.5 Plus 2026-02-15 when lower sample workload cost matters most: $0.11.
- Llama 4 Scout offers 10M context with $0.23 sample workload cost.
- Owl Alpha offers 1.05M context with $0 sample workload cost.
- DeepSeek V4 Flash offers 1.05M context with $0.2 sample workload cost.
- DeepSeek V4 Pro offers 1.05M context with $0.87 sample workload cost.
- DeepSeek V4 Flash · DeepSeek · #1
- Hy3 preview · Tencent · #2
- Claude Opus 4.7 · Anthropic · #3
- Claude Sonnet 4.6 · Anthropic · #4
Cheaper alternatives
Review low-cost models sorted by a standard 1M input plus 500K output workload.
Open cheapest modelsLarger context alternatives
Find models with larger context windows for RAG, long documents, and codebase review.
Open largest context modelsProvider catalogs
Compare models within provider hubs before choosing a final API vendor.
Open provider hubsQwen catalog
Review all tracked Qwen models before deciding whether this matchup is the right shortlist.
Open Qwen modelsByteDance Seed catalog
Check other ByteDance Seed models with comparable pricing, context, or release timing.
Open ByteDance Seed modelsThe Qwen3.5 native vision-language series Plus models are built on a hybrid architecture that integrates linear attention mechanisms with sparse mixture-of-experts models, achieving higher inference efficiency. In a variety of...
Seed 1.6 Flash is an ultra-fast multimodal deep thinking model by ByteDance Seed, supporting both text and visual understanding. It features a 256k context window and can generate outputs of...