API cost decision in 10 seconds

🔥GLM 5.1 vs 🔥gpt-oss-120b

Pick gpt-oss-120b for lower cost; pick GLM 5.1 only if the larger context window matters more.

Pricing data updated:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick gpt-oss-120b for lower cost; pick GLM 5.1 only if the larger context window matters more.

On the standard 1M input plus 500K output workload, gpt-oss-120b is estimated at $0.13 vs $2.52 for GLM 5.1, saving $2.39 (94.9% lower).

Cost-first pickgpt-oss-120b
Context-first pickGLM 5.1
Sample savings$2.3994.9%
10x traffic gap$23.91

GLM 5.1 has more context, but gpt-oss-120b saves $2.39 on the standard workload. At 10x that traffic, the same price gap is about $23.91. Use the calculator below to replace the sample workload with your own token volume.

Cheaper input gpt-oss-120b $0.98 vs $0.039 / 1M

gpt-oss-120b is $0.94 cheaper per 1M input tokens (96% lower; 25.1x difference).

Cheaper output gpt-oss-120b $3.08 vs $0.18 / 1M

gpt-oss-120b is $2.9 cheaper per 1M output tokens (94.2% lower; 17.1x difference).

Larger context GLM 5.1 202.75K vs 131.07K

GLM 5.1 has 71.68K more context (1.55x larger).

Sample workload gpt-oss-120b $2.52 vs $0.13

gpt-oss-120b is $2.39 cheaper on the standard workload (94.9% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
GLM 5.1 Calculating… Estimated API cost
gpt-oss-120b 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

gpt-oss-120b has the lower input price; gpt-oss-120b has the lower output price; GLM 5.1 offers the larger context window. For the 1M input plus 500K output sample, gpt-oss-120b 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 $0.13 for gpt-oss-120b.

Best Fit

Choose GLM 5.1 when you care most about larger context window.

Choose gpt-oss-120b when you care most about lower input-token price, and lower output-token price.

Decision Notes
  • On the standard 1M input plus 500K output workload, gpt-oss-120b is estimated at $0.13 vs $2.52 for GLM 5.1, saving $2.39 (94.9% lower).
  • gpt-oss-120b is $2.39 cheaper on the standard workload (94.9% lower).
  • gpt-oss-120b is $0.94 cheaper per 1M input tokens (96% lower; 25.1x difference).
  • gpt-oss-120b is $2.9 cheaper per 1M output tokens (94.2% lower; 17.1x difference).
  • GLM 5.1 has 71.68K more context (1.55x larger).
Head-to-Head Specs
Feature🔥GLM 5.1
(Z.ai)		🔥gpt-oss-120b
(OpenAI)
Input Price
prompt tokens per 1M		$0.98$0.039
Completion Price
per 1M tokens		$3.08$0.18
Sample Workload Cost
1M input + 500K output		$2.52$0.13
Context Window202.75K131.07K
Release Date
Popularity Rank
current rank		#13#16

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productiongpt-oss-120bOn the standard 1M input plus 500K output workload, gpt-oss-120b is estimated at $0.13 vs $2.52 for GLM 5.1, saving $2.39 (94.9% lower).
High-volume input processinggpt-oss-120bLower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsgpt-oss-120bLower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workGLM 5.1A 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 $0.22 sample workload cost.

Cheaper alternatives

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

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Larger context alternatives

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

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Provider catalogs

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Z.ai catalog

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OpenAI catalog

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

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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...

gpt-oss-120b

gpt-oss-120b is an open-weight, 117B-parameter Mixture-of-Experts (MoE) language model from OpenAI designed for high-reasoning, agentic, and general-purpose production use cases. It activates 5.1B parameters per forward pass and is optimized...