API cost decision in 10 seconds

GLM 4.6 vs gpt-oss-20b (free)

Pick gpt-oss-20b (free) for lower cost; pick GLM 4.6 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 gpt-oss-20b (free) for lower cost; pick GLM 4.6 only if the larger context window matters more.

On the standard 1M input plus 500K output workload, gpt-oss-20b (free) is estimated at $0 vs $1.3 for GLM 4.6, saving $1.3 (100% lower).

Cost-first pickgpt-oss-20b (free)
Context-first pickGLM 4.6
Sample savings$1.3100%
10x traffic gap$13

GLM 4.6 has more context, but gpt-oss-20b (free) saves $1.3 on the standard workload. At 10x that traffic, the same price gap is about $13. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

gpt-oss-20b (free) stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickGLM 4.6gpt-oss-20b (free)
Input-heavy / RAG5M input + 500K outputgpt-oss-20b (free)$3.02$0
Balanced workload1M input + 1M outputgpt-oss-20b (free)$2.17$0
Output-heavy chatbot1M input + 5M outputgpt-oss-20b (free)$9.13$0
Cheaper input gpt-oss-20b (free) $0.43 vs $0 / 1M

gpt-oss-20b (free) is free for input tokens while GLM 4.6 costs $0.43 per 1M tokens.

Cheaper output gpt-oss-20b (free) $1.74 vs $0 / 1M

gpt-oss-20b (free) is free for output tokens while GLM 4.6 costs $1.74 per 1M tokens.

Larger context GLM 4.6 202.75K vs 131.07K

GLM 4.6 has 71.68K more context (1.55x larger).

Sample workload gpt-oss-20b (free) $1.3 vs $0

gpt-oss-20b (free) is free for the standard workload while the other model is estimated at $1.3.

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
GLM 4.6 Calculating… Estimated API cost
gpt-oss-20b (free) 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-20b (free) has the lower input price; gpt-oss-20b (free) has the lower output price; GLM 4.6 offers the larger context window. For the 1M input plus 500K output sample, gpt-oss-20b (free) is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $1.3 for GLM 4.6 and $0 for gpt-oss-20b (free).

Best Fit

Choose GLM 4.6 when you care most about larger context window.

Choose gpt-oss-20b (free) 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-20b (free) is estimated at $0 vs $1.3 for GLM 4.6, saving $1.3 (100% lower).
  • gpt-oss-20b (free) is free for the standard workload while the other model is estimated at $1.3.
  • gpt-oss-20b (free) is free for input tokens while GLM 4.6 costs $0.43 per 1M tokens.
  • gpt-oss-20b (free) is free for output tokens while GLM 4.6 costs $1.74 per 1M tokens.
  • GLM 4.6 has 71.68K more context (1.55x larger).
Head-to-Head Specs
FeatureGLM 4.6
(Z.ai)		gpt-oss-20b (free)
(OpenAI)
Input Price
prompt tokens per 1M		$0.43$0
Completion Price
per 1M tokens		$1.74$0
Sample Workload Cost
1M input + 500K output		$1.3$0
Context Window202.75K131.07K
Release Date
Popularity#63#72

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productiongpt-oss-20b (free)On the standard 1M input plus 500K output workload, gpt-oss-20b (free) is estimated at $0 vs $1.3 for GLM 4.6, saving $1.3 (100% lower).
High-volume input processinggpt-oss-20b (free)Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsgpt-oss-20b (free)Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workGLM 4.6A 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 4.6 when lower sample workload cost matters most: $0.
  • GLM 4 32B can replace GLM 4.6 when lower sample workload cost matters most: $0.15.
  • GLM 4.7 Flash can replace GLM 4.6 when lower sample workload cost matters most: $0.26.
  • GLM 4.5 Air can replace GLM 4.6 when lower sample workload cost matters most: $0.54.
Larger context near this budget

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

Z.ai catalog

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

Open Z.ai models

OpenAI catalog

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

Open OpenAI models
GLM 4.6

Compared with GLM-4.5, this generation brings several key improvements: Longer context window: The context window has been expanded from 128K to 200K tokens, enabling the model to handle more complex...

gpt-oss-20b (free)

gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for...