API cost decision in 10 seconds

GLM 4.5 Air vs gpt-oss-20b

Pick gpt-oss-20b when budget is the priority.

Page updated: 2026-05-26T19:08:13Z Data confirmed: 2026-05-26T20:08:05Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick gpt-oss-20b when budget is the priority.

On the standard 1M input plus 500K output workload, gpt-oss-20b is estimated at $0.1 vs $0.54 for GLM 4.5 Air, saving $0.44 (81.7% lower).

Cost-first pickgpt-oss-20b

Context-first pickBoth models

Sample savings$0.4481.7%

10x traffic gap$4.45

The reported context window is tied, so cost and provider fit carry more weight. At 10x that traffic, the same price gap is about $4.45. 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 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	GLM 4.5 Air	gpt-oss-20b
Input-heavy / RAG	5M input + 500K output	gpt-oss-20b	$1.04	$0.22
Balanced workload	1M input + 1M output	gpt-oss-20b	$0.96	$0.17
Output-heavy chatbot	1M input + 5M output	gpt-oss-20b	$4.33	$0.73

Cheaper input gpt-oss-20b $0.125 vs $0.03 / 1M

gpt-oss-20b is $0.1 cheaper per 1M input tokens (76% lower; 4.17x difference).

Cheaper output gpt-oss-20b $0.84 vs $0.14 / 1M

gpt-oss-20b is $0.7 cheaper per 1M output tokens (83.3% lower; 6x difference).

Larger context Tie 131.07K vs 131.07K

Both models report the same context window at 131.07K tokens.

Sample workload gpt-oss-20b $0.54 vs $0.1

gpt-oss-20b is $0.44 cheaper on the standard workload (81.7% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

GLM 4.5 Air Calculating… Estimated API cost

gpt-oss-20b 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 has the lower input price; gpt-oss-20b has the lower output price; both models report the same context window. For the 1M input plus 500K output sample, gpt-oss-20b is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.54 for GLM 4.5 Air and $0.1 for gpt-oss-20b.

Best Fit

Choose GLM 4.5 Air when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Choose gpt-oss-20b 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 is estimated at $0.1 vs $0.54 for GLM 4.5 Air, saving $0.44 (81.7% lower).
gpt-oss-20b is $0.44 cheaper on the standard workload (81.7% lower).
gpt-oss-20b is $0.1 cheaper per 1M input tokens (76% lower; 4.17x difference).
gpt-oss-20b is $0.7 cheaper per 1M output tokens (83.3% lower; 6x difference).
Both models report the same context window at 131.07K tokens.

Head-to-Head Specs

Feature	GLM 4.5 Air (Z.ai)	gpt-oss-20b (OpenAI)
Input Price prompt tokens per 1M	$0.125	$0.03
Completion Price per 1M tokens	$0.84	$0.14
Sample Workload Cost 1M input + 500K output	$0.54	$0.1
Context Window	131.07K	131.07K
Release Date	2025-07-25	2025-08-05
Popularity	#37	#67

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	gpt-oss-20b	On the standard 1M input plus 500K output workload, gpt-oss-20b is estimated at $0.1 vs $0.54 for GLM 4.5 Air, saving $0.44 (81.7% lower).
High-volume input processing	gpt-oss-20b	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	gpt-oss-20b	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Tie	A 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 4.5 Air when lower sample workload cost matters most: $0.
GLM 4 32B can replace GLM 4.5 Air when lower sample workload cost matters most: $0.15.
GLM 4.7 Flash can replace GLM 4.5 Air when lower sample workload cost matters most: $0.26.
gpt-oss-120b (free) can replace gpt-oss-20b when lower sample workload cost matters most: $0.

Larger context near this budget

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.
Gemini 2.5 Flash Lite offers 1.05M context with $0.3 sample workload cost.

Popular competitors

DeepSeek V4 Flash · DeepSeek · #1
Hy3 preview · Tencent · #2
Claude Opus 4.7 · Anthropic · #3
Claude Sonnet 4.6 · Anthropic · #4

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Provider catalogs

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Z.ai catalog

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OpenAI catalog

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GLM 4.5 Air

GLM-4.5-Air is the lightweight variant of our latest flagship model family, also purpose-built for agent-centric applications. Like GLM-4.5, it adopts the Mixture-of-Experts (MoE) architecture but with a more compact parameter...

gpt-oss-20b

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...