Webpage test is not capturing FCP correctly

Support
1

Hi,

It seems like few metrics are not captured correctly. Please check the following link. We could see the first content showing up in 4.5 second but FCP is showing it as 7.185 sec.
https://www.webpagetest.org/result/231212_BiDc9F_59Y/1/details/#waterfall_view_step1

image
image1207×607 54 KB

your early response will be much appreciated.

Thanks,
Saurabh

2

Hello Saurabh,

I suggest you to contact webpagetest support (Support@webpagetest.org) so that we could look into this issue.

Thank you
Atib

3

Looking at the raw json, it looks like the page unloads and loads another page after the progress indicator. There is a fcp at 4348, an unload event at 6253 and then another fcp at 7184.

chromeUserTiming: [
{
name: "navigationStart",
time: 2
},
{
name: "fetchStart",
time: 7
},
{
name: "navigationStart",
time: 29
},
{
name: "domLoading",
time: 29
},
{
name: "responseEnd",
time: 29
},
{
name: "domInteractive",
time: 29
},
{
name: "domContentLoadedEventStart",
time: 29
},
{
name: "domContentLoadedEventEnd",
time: 29
},
{
name: "domComplete",
time: 29
},
{
name: "responseEnd",
time: 205
},
{
name: "unloadEventStart",
time: 210
},
{
name: "unloadEventEnd",
time: 210
},
{
name: "markAsMainFrame",
time: 210
},
{
name: "commitNavigationEnd",
time: 210
},
{
name: "domLoading",
time: 210
},
{
name: "domInteractive",
time: 4346
},
{
name: "domContentLoadedEventStart",
time: 4347
},
{
name: "domContentLoadedEventEnd",
time: 4347
},
{
name: "domComplete",
time: 4347
},
{
name: "loadEventStart",
time: 4347
},
{
name: "firstPaint",
time: 4348
},
{
name: "firstContentfulPaint",
time: 4348
},
{
name: "firstImagePaint",
time: 4348
},
{
name: "firstMeaningfulPaintCandidate",
time: 4348
},
{
name: "firstMeaningfulPaint",
time: 4348
},
{
name: "firstMeaningfulPaint",
time: 4348
},
{
name: "loadEventEnd",
time: 4348
},
{
name: "navigationStart",
time: 5494
},
{
name: "fetchStart",
time: 5504
},
{
name: "responseEnd",
time: 6231
},
{
name: "unloadEventStart",
time: 6253
},
{
name: "unloadEventEnd",
time: 6253
},
{
name: "commitNavigationEnd",
time: 6262
},
{
name: "domLoading",
time: 6265
},
{
name: "firstMeaningfulPaintCandidate",
time: 7184
},
{
name: "firstImagePaint",
time: 7184
},
{
name: "firstContentfulPaint",
time: 7184
},
{
name: "firstPaint",
time: 7184
},
{
name: "domInteractive",
time: 7197
},
{
name: "domContentLoadedEventStart",
time: 7197
},
{
name: "domContentLoadedEventEnd",
time: 7198
},
{
name: "LayoutShift",
time: 7808
},
{
name: "LayoutShift",
time: 7965
},
{
name: "LayoutShift",
time: 8127
},
{
name: "firstMeaningfulPaintCandidate",
time: 8179
},
{
name: "firstMeaningfulPaint",
time: 8179
},
{
name: "firstMeaningfulPaint",
time: 8179
},
{
name: "LayoutShift",
time: 8409
},
{
name: "LayoutShift",
time: 8547
},
{
name: "LayoutShift",
time: 8744
},
{
name: "LayoutShift",
time: 8860
},
{
name: "LayoutShift",
time: 9153
},
{
name: "LayoutShift",
time: 10995
},
{
name: "LayoutShift",
time: 11136
},
{
name: "LayoutShift",
time: 11353
},
{
name: "LayoutShift",
time: 11518
},
{
name: "LayoutShift",
time: 11837
},
{
name: "LayoutShift",
time: 11952
},
{
name: "domComplete",
time: 15278
},
{
name: "loadEventStart",
time: 15278
},
{
name: "loadEventEnd",
time: 15351
},
{
name: "LargestImagePaint",
time: 9677
},
{
name: "LargestContentfulPaint",
time: 9677
},
{
name: "LargestTextPaint",
time: 8179
},
{
name: "TotalLayoutShift",
value: 0.8696946265999999
},
{
name: "CumulativeLayoutShift",
value: 0.7964873445999999
}
],