# measure the rendering time in vtk.js using "GetLastRenderTimeInSeconds()"
**URL:** https://discourse.vtk.org/t/measure-the-rendering-time-in-vtk-js-using-getlastrendertimeinseconds/13771
**Category:** Web
**Created:** [April 22, 2024, 12:09pm UTC](https://discourse.vtk.org/t/measure-the-rendering-time-in-vtk-js-using-getlastrendertimeinseconds/13771 "2024-04-22T12:09:01Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Mohammed\_AboArab](https://discourse.vtk.org/u/Mohammed_AboArab)
#### Post date: [April 22, 2024, 12:09pm UTC](https://discourse.vtk.org/t/measure-the-rendering-time-in-vtk-js-using-getlastrendertimeinseconds/13771/1 "2024-04-22T12:09:01Z")
I get an error when I used the following:
```auto
const lastRenderTime = renderWindow.GetLastRenderTimeInSeconds();
console.log(`Last Render Time: ${lastRenderTime} seconds`);
```
---
### Author:  [@Forrest](https://discourse.vtk.org/u/Forrest)
#### Post date: [April 22, 2024, 2:19pm UTC](https://discourse.vtk.org/t/measure-the-rendering-time-in-vtk-js-using-getlastrendertimeinseconds/13771/2 "2024-04-22T14:19:46Z")
The property is on `vtkRenderer`, not `vtkRenderWindow`: `renderer.getLastRenderTimeInSeconds()`.
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### Author:  [@Mohammed\_AboArab](https://discourse.vtk.org/u/Mohammed_AboArab)
#### Post date: [April 22, 2024, 2:58pm UTC](https://discourse.vtk.org/t/measure-the-rendering-time-in-vtk-js-using-getlastrendertimeinseconds/13771/3 "2024-04-22T14:58:47Z")
Thank you for answering, but I get the following error:
TypeError: vtkRenderer.GetLastRenderTimeInSeconds is not a function
---
### Author:  [@Mohammed\_AboArab](https://discourse.vtk.org/u/Mohammed_AboArab)
#### Post date: [April 22, 2024, 2:59pm UTC](https://discourse.vtk.org/t/measure-the-rendering-time-in-vtk-js-using-getlastrendertimeinseconds/13771/4 "2024-04-22T14:59:50Z")
> [@Forrest](#):
>
> renderer.getLastRenderTimeInSeconds()
It gives me the same error