Claude Opus 5.5 vs GLM 5.3 FlashX
API pricing, context, and independently measured performance, side by side. GLM 5.3 FlashX starts 91% cheaper on input than Claude Opus 5.5 at list prices.
Claude Opus 5.5
Anthropic · released Sep 22, 2026
Best input$4.00 / MTok
Best output$20.00 / MTok
Context1M
Providers13
Fastest measured3.7s° TTFT · 216 tok/s
VisionToolsReasoningStructured outputPrompt caching
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
Cheapest providers, measuredUSD / MTOK
| MODEL | PROVIDER | INPUT | OUTPUT | TTFT | TPS | SMOKE |
|---|---|---|---|---|---|---|
| Claude Opus 5.5 |  Amazon Bedrock | $4.00 | $20.00 | — | — | — |
| Claude Opus 5.5 |  Azure | $4.00 | $20.00 | 3.7s° | 216° tok/s | — |
| Claude Opus 5.5 |  Google | $4.00 | $20.00 | 3.9s° | 164° tok/s | — |
| GLM 5.3 FlashX |  Z.AI | $0.37 | $1.25 | 2.2s° | 194° tok/s | — |
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