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GoogleChrome / lighthouse

Automated auditing, performance metrics, and best practices for the web.
https://developer.chrome.com/docs/lighthouse/overview/
Apache License 2.0
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NO_FCP when tab is in the background #6154

Open serge22 opened 6 years ago

serge22 commented 6 years ago

Provide the steps to reproduce

  1. Run LH on any URL, for example https://www.google.com/

What is the current behavior?

NO_FCP, cannot measure performance. No matter is it a remote server or running on a localhost. Tried to do the same in new clean Chrome profile and got the same issue. CLI works just fine. untitled

What is the expected behavior?

Expect LH to evaluate performance and check pwa checklist

Environment Information

Related issues

6134

serge22 commented 6 years ago

After reading the LH documentation, I found it's recommended to use the Chrome DevTools and it works well.

exterkamp commented 6 years ago

So can you replicate this in the extension still? I ran it on the extension, and it seems to work fine.

google_run

Chrome v69.0.3497.100/LH 3.2.1

serge22 commented 6 years ago

Reinstalled the extension and it does not work for me still. Could it depends on OS? I'm using the Ubuntu 18.04.1 Video of the process: https://youtu.be/pCoOqlKcrxw

RicardoNeves commented 6 years ago

Reinstalled the extension and it does not work for me still. Could it depends on OS? I'm using the Ubuntu 18.04.1 Video of the process: https://youtu.be/pCoOqlKcrxw

It doesn't work for me neither on Manjaro Linux.

patrickhulce commented 6 years ago

Thanks very much for the video @serge22! This is very strange, it might be linux specific. It's especially odd given that the page load looks completely normal, there's just something wrong with the trace Lighthouse is getting from Chrome.

patrickhulce commented 6 years ago

I spun up a Ubuntu 18.04.1 LTS VM and was unable to repro this with Chrome/71.0.3559.0

Could you try updating Chrome @serge22 and let us know if that solves the issue?

wardpeet commented 6 years ago

I'll give it a go in the morning as well on my Ubuntu machine and Chrome stable

wardpeet commented 6 years ago

ubuntu 18.04.1 on chrome 69.0.3497.100

image

do you have it only on that machine? You could try chromium or canary and see if that works. How did you install chrome-stable on ubuntu?

ciwchris commented 6 years ago

Same here using Chromium: Version 69.0.3497.100 (Official Build) Arch Linux (64-bit)

But it does function correctly from the devtools

brad-decker commented 6 years ago

Chrome Version 69.0.3497.100 (Official Build) (64-bit) Manjaro (so, arch) doesn't work as extension or dev tools. NO_FCP error

alsessions commented 6 years ago

Doesn't work from either Dev Tools or the extension. Using Mint 18.3 and Chrome Version 69.0.3497.100 (Official Build) (64-bit).

dev_tools

paulbjensen commented 5 years ago

Seeing the same issue, computer details:

Chrome Version 71.0.3578.80 (Official Build) (64-bit) Mac OS Mojave Version 10.14 (18A391) MacBook Pro (Retina, 13-inch, Mid 2014)

webschik commented 5 years ago

Hi,

It happens all the time when you have the next situation:

I've created a minimal reproducible demo for that https://github.com/webschik/lighthouse-no-fcp P.S. In the production I've fixed that by adding of the small static text to the page.

JacobMGEvans commented 5 years ago

I was trying to audit an old website that was receiving these errors as well. Curious what are some possible likely causes of this?

edit:

patrickhulce commented 5 years ago

We've got a fix in v4 that should hopefully mitigate many of these cases. If you're experiencing this, give it whirl with the latest extension and let us know how it goes.

meikidd commented 5 years ago

Same issue here, it doesn't work either from DevTools or Chrome extension, computer details:

=============

Error Report from Chrome extension:

Lighthouse Version: 4.2.0 Lighthouse Commit: 35b285b87d681905777ed2545e48292312910485 Chrome Version: 73.0.3683.75 Initial URL: https://airhorner.com/ Error Message: NO_FCP Stack Trace:

LHError: NO_FCP
    at chrome-extension://blipmdconlkpinefehnmjammfjpmpbjk/scripts/lighthouse-ext-bundle.js:21525:8
rvalitov commented 5 years ago

Same issue on Windows, it doesn't work either from DevTools or Chrome extension, computer details:

Error Report from Chrome extension:

Channel: DevTools
Initial URL: http://krooktjader.rproducts.eu/kontakt
Chrome Version: 74.0.3729.131
Stack Trace: LHError: NO_FCP
    at eval (chrome-devtools://devtools/remote/serve_file/@518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f/audits2_worker/audits2_worker_module.js:1199:206)
huang-x-h commented 5 years ago

Same issue on Mac

Enviroment:

Error:

Channel: DevTools
Initial URL: https://uworker.unicloud.com/web-oa/page/index.html#/dashboard
Chrome Version: 74.0.3729.131
Stack Trace: LHError: NO_FCP
    at eval (chrome-devtools://devtools/remote/serve_file/@518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f/audits2_worker/audits2_worker_module.js:1199:206)
GeranPele commented 5 years ago

Same issue on Mac and Windows. Canary and Stable. I'm actually not able to copy the error because the dialog overlays the information and is gone when I click cancel, but it is the same as the above

marcus-d5r commented 5 years ago

Same Issue, my setup:

MacBook Pro 2015 MacOS Mojave 10.14.4 (18E226) Chrome Version 74.0.3729.157 (Official Build) (64-bit)

Am trying to audit a static site built with Gatsby.

Error message:

`NO_FCP

Channel: DevTools
Initial URL: https://digitalerbauer.de/
Chrome Version: 74.0.3729.157
Stack Trace: LHError: NO_FCP
    at eval (chrome-devtools://devtools/remote/serve_file/@7b16107ab85c5364cdcd0b2dea2539a1f2dc327a/audits2_worker/audits2_worker_module.js:1199:206)
bethharvey1 commented 5 years ago

Same issue on MacOS using Dev Tools. My setup is:

Error Report NO_FCP

Channel: DevTools
Initial URL: https://www.etsy.com/
Chrome Version: 74.0.3729.169
Stack Trace: LHError: NO_FCP
    at eval (chrome-devtools://devtools/remote/serve_file/@78e4f8db3ce38f6c26cf56eed7ae9b331fc67ada/audits2_worker/audits2_worker_module.js:1199:206)
jacobpackert commented 5 years ago

I got this just now. Macbook Pro 15 inch 2018 MacOS Mojave 10.14.5 Chrome 74.0.3729.169 Ran LH from Chrome Dev Tools.

Error message: NO_FCP

Channel: DevTools
Initial URL: http://dinesen.com/
Chrome Version: 74.0.3729.169
Stack Trace: LHError: NO_FCP
    at eval (chrome-devtools://devtools/remote/serve_file/@78e4f8db3ce38f6c26cf56eed7ae9b331fc67ada/audits2_worker/audits2_worker_module.js:1199:206)
vikram0207 commented 5 years ago

Getting the same Error

Macbook Air: 10.13.6 Chrome: Version 74.0.3729.169 (Official Build) (64-bit)

Error Message: NO_FCP

Channel: DevTools
Initial URL: https://www.paisabazaar.com/cards-ssr
Chrome Version: 74.0.3729.169
Stack Trace: LHError: NO_FCP
    at eval (chrome-devtools://devtools/remote/serve_file/@78e4f8db3ce38f6c26cf56eed7ae9b331fc67ada/audits2_worker/audits2_worker_module.js:1199:206)
millette commented 5 years ago

NO_FCP error too on my old Debian Jessie (8.11) thru dev tools, but it works on the command line.

venkate5hgunda commented 5 years ago

Getting the same error when debugging in Localhost on IIS Express [Visual Studio]:

NO_FCP

Channel: DevTools
Initial URL: https://localhost.randomwebsite.com:44300/en-us/shop/samsung-65-inch-flat-4k-ultra-hd-hdr-smart-tv-un65nu6900fxza/apd/aa283176/tv-home-theater
Chrome Version: 74.0.3729.169
Stack Trace: LHError: NO_FCP
    at eval (chrome-devtools://devtools/remote/serve_file/@78e4f8db3ce38f6c26cf56eed7ae9b331fc67ada/audits2_worker/audits2_worker_module.js:1199:206)

Computer Details: Dell Precision 15: Windows 10 Enterprise (10.0.17134 Build 17134) Chrome: 74.0.3729.169

danhilltech commented 5 years ago

I have this issue only when the actual page isn't visible on my screen. If I move devtools to the side and have the window active, the FCP events etc. fire fine.

millette commented 5 years ago

I already mentionned it wasn't working for my old Debian in https://github.com/GoogleChrome/lighthouse/issues/6154#issuecomment-504127802 but as @danhilltech stated, it works if the browser is shown.

connorjclark commented 5 years ago

@danhilltech that's expected and unavoidable - Chrome will prioritize rendering completely if the window is not visible.

millette commented 5 years ago

@connorjclark It was working before even if the browser window was hidden.

brendankenny commented 5 years ago

@millette it's possible there was a Chrome renderer optimization implemented then, though at least on the Mac it's been this way for quite a while.

There's not much we can do here: if the browser decides to lazily render only when the tab becomes visible again, Lighthouse can't reliably measure when it would have rendered if the tab had been visible.

Maybe we could improve the error message suggesting to check that the tab was in the foreground?

millette commented 5 years ago

Maybe we could improve the error message suggesting to check that the tab was in the foreground?

@brendankenny That would be appreciated :-)

lmribeiro commented 5 years ago

Not working for me. Screenshot from 2019-07-11 10-06-07

saifalfalah commented 5 years ago

Had the same issue. @danhilltech's technique worked. Put the focus on the actual page and it works.

x5engine commented 5 years ago

just check no throttling and it should work even if it is a little bit slow

x5engine commented 5 years ago

image

x5engine commented 5 years ago

lighthouse in vscode terminal is not working either! on windows 10

vscode 2019

foladipo commented 5 years ago

Thanks a lot @saifalfalah! The solution you explained worked for me too.

dudeisbrendan03 commented 5 years ago

Reproduced on Chrome OS 76.0.3809.102, @danhilltech's solution worked without a problem.

adityapatadia commented 5 years ago

@danhilltech and @saifalfalah solutions might only work when using GUI version. What if I am using chrome headless with puppeteer?

brendankenny commented 4 years ago

https://github.com/GoogleChrome/chrome-launcher/pull/170 should have solved this for the CLI. #9650 will add a warning if the tested tab was backgrounded and Lighthouse should be run again.

paulirish commented 3 years ago

also, #11579 (available in 6.5.0+) provided a more helpful error message:

The page did not paint any content. Please ensure you keep the browser window in the foreground during the load and try again. (NO_FCP)

The browser tab needs to remain visible while it's loading for Lighthouse to work.

connorjclark commented 2 years ago

Need to update this old PR: #9650