GLM 4.5 Air API Pricing
Z.ai (GLM) · context window 131K · prices updated 2026-09-15
Where GLM 4.5 Air sits on price
At $0.85 per million output tokens, GLM 4.5 Air is a mid tier model — 2.4× cheaper than the median output price of $2.08, which puts it cheaper than 71% and pricier than 29% of the models we track. It sits 4th cheapest of the 17 Z.ai (GLM) models we track. Output costs 6.5× more than input here, so anything that makes the model write less — tighter instructions, structured output, lower max_tokens — moves the bill more than trimming the prompt.
Cached input is 81% cheaper. On an input-heavy workload you need roughly a 31% cache-hit rate to take 25% off the input line — reachable for chatbots and agents that resend the same system prompt and history.
What real workloads cost on GLM 4.5 Air
These three workloads are the ones teams actually run on a mid-priced model — a $0.85/1M model is not bought for the same job as one ten times the price.
| Workload | Per request | Per month |
|---|---|---|
| Support chatbot — 500 conversations/day (5K in / 1.4K out) Conversation history re-sent each turn — the classic prompt-caching win. | $0.0018 | $27.60 |
| Document pipeline — 10K docs/day (3K in / 500 out) Batch-friendly: no user waiting, so a ~50% batch discount usually applies. | $0.0008 | $245 |
| Small app — 1K requests/day (500 in / 150 out) The baseline most side projects actually run at. | $0.0002 | $5.77 |
Model your exact traffic in the API cost calculator — it preloads GLM 4.5 Air with caching and batch options.
GLM 4.5 Air price history
GLM 4.5 Air's price has not moved since we began tracking it on Aug 2, 2026 — 44 days of stability in a market where 78 of the 334 models we track have repriced over the same period, including 9 of Z.ai (GLM)'s own 17 models.
Change-points from our daily price snapshots (tracking since Aug 2, 2026; intraday moves between snapshots are not captured).
GLM 4.5 Air vs Qwen3 Coder Next
The closest-priced alternative from another vendor is Qwen3 Coder Next (Alibaba (Qwen)) — 6% cheaper on output, with $0.01 less per million input tokens. When two models land this close on price, the decision is quality on your own workload, not the price sheet: run 50 real requests through both and compare.
See Qwen3 Coder Next pricing →Cheaper alternatives
More Z.ai (GLM) models
Frequently asked questions
› How much does the GLM 4.5 Air API cost?
GLM 4.5 Air costs $0.13 per million input tokens and $0.85 per million output tokens, with cached input at $0.025 per million (81% cheaper). That works out to roughly 1,176,471 output tokens per dollar.
› What does the support chatbot workload cost on GLM 4.5 Air?
Support chatbot — 500 conversations/day (5K in / 1.4K out) costs about $0.0018 per request and $27.60 per month on GLM 4.5 Air. Conversation history re-sent each turn — the classic prompt-caching win.
› What does it cost to fill GLM 4.5 Air's 131K context window?
Sending 131K of input in a single request costs $0.017 at $0.13 per million tokens — before any output. With prompt caching that same fill drops to about $0.0033 on repeat requests. This is why large context windows are cheap to advertise and expensive to actually use.
› Is GLM 4.5 Air worth the price?
GLM 4.5 Air sits in the middle of the market (4 of 17 by price within Z.ai (GLM)). The honest test is a routing experiment: send the same 200 real requests to this model and to a tier below, and compare failure rate against the price gap — most teams find a majority of traffic never needed the pricier model.