GLM 5.3 FlashX vs GLM 5.3 Prime
API pricing, context, and independently measured performance, side by side. GLM 5.3 FlashX starts 87% cheaper on input than GLM 5.3 Prime at list prices.
GLM 5.3 FlashX
Z.ai · released Sep 18, 2026
Best input$0.37 / MTok
Best output$1.25 / MTok
Context1.05M
Providers1
Fastest measured2.2s° TTFT · 194 tok/s
VisionToolsReasoningStructured outputPrompt caching
GLM 5.3 Prime
Z.ai · released Sep 23, 2026
Best input$2.80 / MTok
Best output$8.80 / MTok
Context1M
Providers1
Fastest measured—
ToolsReasoningStructured outputPrompt caching
Cheapest providers, measuredUSD / MTOK
| MODEL | PROVIDER | INPUT | OUTPUT | TTFT | TPS | SMOKE |
|---|---|---|---|---|---|---|
| GLM 5.3 FlashX |  Z.AI | $0.37 | $1.25 | 2.2s° | 194° tok/s | — |
| GLM 5.3 Prime |  Alibaba | $2.80 | $8.80 | — | — | — |
TTFT/TPS: ModelIndex-measured medians (P50, trailing 21d) · chat10k profile (~10K in / 200 out) · ° = measured via OpenRouter routing (adds a hop) · SMOKE: of 5 programmatic capability probes passed · methodology v1.1 — full details on each model page