GLM 5.3 FlashX API Pricing
Z.ai (GLM) · context window 1M · prices updated 2026-09-29
Where GLM 5.3 FlashX sits on price
At $1.25 per million output tokens, GLM 5.3 FlashX is a mid tier model — 1.8× cheaper than the median output price of $2.20, which puts it cheaper than 63% and pricier than 37% of the models we track. It sits 6th cheapest of the 18 Z.ai (GLM) models we track. Output costs 3.4× input, the usual spread — trim both, starting with the answer length.
Cached input is 76% cheaper. On an input-heavy workload you need roughly a 33% 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 FlashX
These three workloads are the ones teams actually run on a mid-priced model — a $1.25/1M 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. | $0.0036 | $54.00 |
| Document pipeline — 10K docs/day (3K in / 500 out) Batch-friendly: no user waiting, so a ~50% batch discount usually applies. | $0.0017 | $521 |
| Long-context analysis — 200 runs/day (250K in / 4K out) Only possible on large-context models; input cost is nearly the whole bill. | $0.0975 | $585 |
Model your exact traffic in the API cost calculator — it preloads GLM 5.3 FlashX with caching and batch options.
GLM 5.3 FlashX price history
GLM 5.3 FlashX's price has not moved since we began tracking it on Sep 19, 2026 — 10 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 19, 2026; intraday moves between snapshots are not captured).
GLM 5.3 FlashX vs Gemini 3.5 Flash Lite (batch)
The closest-priced alternative from another vendor is Gemini 3.5 Flash Lite (batch) (Google) — priced within a rounding error on output, with $0.22 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 Lite (batch) pricing →Cheaper alternatives
More Z.ai (GLM) models
Frequently asked questions
› How much does the GLM 5.3 FlashX API cost?
GLM 5.3 FlashX costs $0.37 per million input tokens and $1.25 per million output tokens, with cached input at $0.09 per million (76% cheaper). That works out to roughly 800,000 output tokens per dollar.
› What does the support chatbot workload cost on GLM 5.3 FlashX?
Support chatbot — 500 conversations/day (5K in / 1.4K out) costs about $0.0036 per request and $54.00 per month on GLM 5.3 FlashX. Conversation history re-sent each turn — the classic prompt-caching win.
› What does it cost to fill GLM 5.3 FlashX's 1M context window?
Sending 1M of input in a single request costs $0.388 at $0.37 per million tokens — before any output. With prompt caching that same fill drops to about $0.0944 on repeat requests. This is why large context windows are cheap to advertise and expensive to actually use.
› Is GLM 5.3 FlashX worth the price?
GLM 5.3 FlashX sits in the middle of the market (6 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.