GLM 5.3 Prime API Pricing
Z.ai (GLM) · context window 1M · prices updated 2026-09-29
Where GLM 5.3 Prime sits on price
At $8.80 per million output tokens, GLM 5.3 Prime is a premium tier model — 4.0× the median output price of $2.20, which puts it cheaper than 24% and pricier than 76% of the models we track. It is the most expensive of the 18 Z.ai (GLM) models we track. Output costs 3.1× input, the usual spread — trim both, starting with the answer length.
Cached input is 80% 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 5.3 Prime
These three workloads are the ones teams actually run on a premium-priced model — a $8.80/1M 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. | $0.0263 | $395 |
| Coding agent — 300 sessions/day (60K in / 12K out) Multi-step loops re-read the same files; caching matters more than raw price. | $0.2736 | $2462 |
| Long-context analysis — 200 runs/day (250K in / 4K out) Only possible on large-context models; input cost is nearly the whole bill. | $0.7352 | $4411 |
Model your exact traffic in the API cost calculator — it preloads GLM 5.3 Prime with caching and batch options.
GLM 5.3 Prime price history
GLM 5.3 Prime's price has not moved since we began tracking it on Sep 24, 2026 — 5 days of stability in a market where 88 of the 353 models we track have repriced over the same period, including 10 of Z.ai (GLM)'s own 18 models.
Change-points from our daily price snapshots (tracking since Sep 24, 2026; intraday moves between snapshots are not captured).
GLM 5.3 Prime vs Gemini 3.5 Flash
The closest-priced alternative from another vendor is Gemini 3.5 Flash (Google) — 2% more expensive on output, with $1.30 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 Gemini 3.5 Flash pricing →Cheaper alternatives
More Z.ai (GLM) models
Frequently asked questions
› How much does the GLM 5.3 Prime API cost?
GLM 5.3 Prime costs $2.80 per million input tokens and $8.80 per million output tokens, with cached input at $0.56 per million (80% cheaper). That works out to roughly 113,636 output tokens per dollar.
› What does the support chatbot workload cost on GLM 5.3 Prime?
Support chatbot — 500 conversations/day (5K in / 1.4K out) costs about $0.0263 per request and $395 per month on GLM 5.3 Prime. Conversation history re-sent each turn — the classic prompt-caching win.
› What does it cost to fill GLM 5.3 Prime's 1M context window?
Sending 1M of input in a single request costs $2.80 at $2.80 per million tokens — before any output. With prompt caching that same fill drops to about $0.56 on repeat requests. This is why large context windows are cheap to advertise and expensive to actually use.
› Is GLM 5.3 Prime worth the price?
GLM 5.3 Prime sits in the middle of the market (18 of 18 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.