GLM-5.3 vs GPT-5.5
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-5.3 costs less (about 81% less than GPT-5.5). GPT-5.5 takes the longer prompt at 1.1M 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-5.3", "messages": [{"role": "user", "content": "Hello"}]}'
# the other one: change the model string
-d '{"model": "openai/gpt-5.5", ...}'Common questions
Which is cheaper, GLM-5.3 or GPT-5.5?
GLM-5.3 is cheaper on a typical mix of 75% input and 25% output tokens, by about 81%. Through Rapid Router both are billed at the provider list price per million tokens, in rupees.
Which has the larger context window?
GPT-5.5, at 1.1M tokens. GLM-5.3 offers 1M tokens.
Can I switch between GLM-5.3 and GPT-5.5 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-5.3 or openai/gpt-5.5).
How do I pay for GLM-5.3 or GPT-5.5 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.