GLM-4.5 & GLM-5 vs GPT-4o: A Practical API Comparison (2026)
Zhipu's GLM family is one of China's most capable model lines — and it's built for agents, function calling, and Chinese. Here's how GLM-4.5 and GLM-5 stack up against GPT-4o on real USD pricing through an OpenAI-compatible endpoint.
Why developers reach for GLM
- Agentic by design. Strong tool-use and function-calling, tuned for multi-step agent workflows rather than single-shot chat.
- Chinese + bilingual fluency. Native-grade Chinese with solid English, ideal for bilingual products.
- Drop-in compatible. Same OpenAI SDK, same message format — just change the
modelfield.
Real USD pricing, side by side
| Model (via AnAiApi) | Input $/1M | Output $/1M | vs GPT-4o input |
|---|---|---|---|
| GLM-4.5 | $1.08 | $3.94 | ~57% cheaper |
| GLM-5 | $1.80 | $5.76 | ~28% cheaper |
| GPT-4o (reference) | $2.50 | $10.00 | — |
GPT-4o figures are OpenAI's published reference rates. GLM rates are the exact USD prices on AnAiApi. GLM-5 is the higher-capability tier; GLM-4.5 is the cost-efficient workhorse.
Which should you pick?
- Pick GLM-4.5 for cost-sensitive, high-volume agent and tool-calling workloads — it undercuts GPT-4o on both input and output.
- Pick GLM-5 when you need the stronger tier for harder reasoning while still paying less than GPT-4o.
- Pick both via AnAiApi and route per task from one client — no separate accounts, one USD bill.
Run GLM in 3 lines
from openai import OpenAI
client = OpenAI(api_key="YOUR_ANAI_API_KEY", base_url="https://www.anaiapi.com/v1")
resp = client.chat.completions.create(
model="glm-5",
messages=[{"role":"user","content":"Plan a 3-step agent that books a meeting and emails the summary."}]
)Ship with GLM today
OpenAI-compatible. USD billing. Free starter credits — no card required.
Create free accountFAQ
Is GLM OpenAI-compatible?
Yes. Point your OpenAI SDK at https://www.anaiapi.com/v1 with an AnAiApi key and call glm-4.5 or glm-5 like any other model.
Does GLM support function calling?
Yes — GLM is tuned for tool-use and agentic flows, so you can pass tools/functions the same way you would with GPT-4o.