GLM-4.5-Air vs GPT OSS 20B
Price in rupees, context and benchmarks side by side; same key, a one-string switch.
Scores from LMArena and Epoch AI, as published; a blank cell means not measured there.
What a month costs on each
On a typical 75/25 input-output mix, GLM-4.5-Air costs less. GLM-4.5-Air takes the longer prompt at 131K tokens. Try your own numbers in the cost calculator.
Call either one
curl https://rapidrouter.ai/api/v1/chat/completions \
-H "Authorization: Bearer $RAPIDROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "z-ai/glm-4.5-air", "messages": [{"role": "user", "content": "Hello"}]}'
# the other one: change the model string
-d '{"model": "openai/gpt-oss-20b", ...}'Common questions
Which is cheaper, GLM-4.5-Air or GPT OSS 20B?
GLM-4.5-Air is cheaper on a typical mix of 75% input and 25% output tokens. Through Rapid Router both are billed at the provider list price per million tokens, in rupees.
Which has the larger context window?
GLM-4.5-Air, at 131K tokens. GPT OSS 20B offers 131K tokens.
Can I switch between GLM-4.5-Air and GPT OSS 20B without changing code?
Yes. Both are callable at https://rapidrouter.ai/api/v1 with the same OpenAI-compatible request; only the model string changes (z-ai/glm-4.5-air or openai/gpt-oss-20b).
How do I pay for GLM-4.5-Air or GPT OSS 20B in India?
Top up a Rapid Router balance with UPI or a card in rupees, get a GST invoice on every recharge, and both models debit that balance per request.