API cost decision in 10 seconds

GLM 5.1 vs Qwen3.5-9B

Pick Qwen3.5-9B when budget and context both matter.

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

Budget verdict

Pick Qwen3.5-9B when budget and context both matter.

On the standard 1M input plus 500K output workload, Qwen3.5-9B is estimated at $0.11 vs $2.52 for GLM 5.1, saving $2.41 (95.4% lower).

Cost-first pickQwen3.5-9B
Context-first pickQwen3.5-9B
Sample savings$2.4195.4%
10x traffic gap$24.05

Qwen3.5-9B is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $24.05. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Qwen3.5-9B stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickGLM 5.1Qwen3.5-9B
Input-heavy / RAG5M input + 500K outputQwen3.5-9B$6.44$0.28
Balanced workload1M input + 1M outputQwen3.5-9B$4.06$0.19
Output-heavy chatbot1M input + 5M outputQwen3.5-9B$16.38$0.79
Cheaper input Qwen3.5-9B $0.98 vs $0.04 / 1M

Qwen3.5-9B is $0.94 cheaper per 1M input tokens (95.9% lower; 24.5x difference).

Cheaper output Qwen3.5-9B $3.08 vs $0.15 / 1M

Qwen3.5-9B is $2.93 cheaper per 1M output tokens (95.1% lower; 20.5x difference).

Larger context Qwen3.5-9B 202.75K vs 262.14K

Qwen3.5-9B has 59.39K more context (1.29x larger).

Sample workload Qwen3.5-9B $2.52 vs $0.11

Qwen3.5-9B is $2.41 cheaper on the standard workload (95.4% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
GLM 5.1 Calculating… Estimated API cost
Qwen3.5-9B 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

Qwen3.5-9B has the lower input price; Qwen3.5-9B has the lower output price; Qwen3.5-9B offers the larger context window. For the 1M input plus 500K output sample, Qwen3.5-9B is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $2.52 for GLM 5.1 and $0.11 for Qwen3.5-9B.

Best Fit

Choose GLM 5.1 when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Choose Qwen3.5-9B when you care most about lower input-token price, lower output-token price, and larger context window.

Decision Notes
  • On the standard 1M input plus 500K output workload, Qwen3.5-9B is estimated at $0.11 vs $2.52 for GLM 5.1, saving $2.41 (95.4% lower).
  • Qwen3.5-9B is $2.41 cheaper on the standard workload (95.4% lower).
  • Qwen3.5-9B is $0.94 cheaper per 1M input tokens (95.9% lower; 24.5x difference).
  • Qwen3.5-9B is $2.93 cheaper per 1M output tokens (95.1% lower; 20.5x difference).
  • Qwen3.5-9B has 59.39K more context (1.29x larger).
Head-to-Head Specs
FeatureGLM 5.1
(Z.ai)		Qwen3.5-9B
(Qwen)
Input Price
prompt tokens per 1M		$0.98$0.04
Completion Price
per 1M tokens		$3.08$0.15
Sample Workload Cost
1M input + 500K output		$2.52$0.11
Context Window202.75K262.14K
Release Date

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionQwen3.5-9BOn the standard 1M input plus 500K output workload, Qwen3.5-9B is estimated at $0.11 vs $2.52 for GLM 5.1, saving $2.41 (95.4% lower).
High-volume input processingQwen3.5-9BLower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsQwen3.5-9BLower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workQwen3.5-9BA larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • GLM 4.5 Air (free) can replace GLM 5.1 when lower sample workload cost matters most: $0.
  • GLM 4 32B can replace GLM 5.1 when lower sample workload cost matters most: $0.15.
  • GLM 4.7 Flash can replace GLM 5.1 when lower sample workload cost matters most: $0.26.
  • GLM 4.5 Air can replace GLM 5.1 when lower sample workload cost matters most: $0.55.
Larger context near this budget
  • Llama 4 Scout offers 10M context with $0.23 sample workload cost.
  • Grok 4.20 offers 2M context with $2.5 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.

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.

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Provider catalogs

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

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Z.ai catalog

Review all tracked Z.ai models before deciding whether this matchup is the right shortlist.

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Qwen catalog

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

Open Qwen models
GLM 5.1

GLM-5.1 delivers a major leap in coding capability, with particularly significant gains in handling long-horizon tasks. Unlike previous models built around minute-level interactions, GLM-5.1 can work independently and continuously on...

Qwen3.5-9B

Qwen3.5-9B is a multimodal foundation model from the Qwen3.5 family, designed to deliver strong reasoning, coding, and visual understanding in an efficient 9B-parameter architecture. It uses a unified vision-language design...