Worker waiting about 10 seconds?!

My Observable often is very slow – loading and rendering a notebook takes 15s. I cannot figure out why. I can see worker- being ‘busy’ (spinning wheel). Inspection reveals that it seems to be waiting – see green bars below. On what, exactly?

What can I do to get rid of those very long waiting times? Any suggestions greatly appreciated.

Sorted by occurrence:

Sorted by (elapsed) Time:

I know I’m not running state of the art iMac (late 2015), OS (Monterey, 12.7.3), and Safari (17.3.1). But I was snappy a couple of macOSes back.

Very curious. I associate that wait time with “waiting for remote server to start the connection”. On the other hand, it says it was served from “(memory)”, which makes me think there isn’t a server involved.

Can you save this view as a HAR file with the top right “Export” button and send it to me? It might contain sensitive details, so it would probably be best to email it to me directly at This will let me dig in a bit more than a screenshot of the network panel.

Thanks for your quick response, Michael!

2MB HAR file sent via e-mail.

For what it’s worth: in the Timelines > Frames view, elapsed time of Frame 73 is 6.77s, and Frame 98 is 5.08s. When opened, both show gazillions of Animation Frames fired.

Thanks for sending that along. Unfortunately I wasn’t able to find anything more from inspecting it. Is this something that is repeatable for you, or does it only happen sometimes?

It is continuous, unfortunately.

I suspect Apple’s planned obsolescence of older platforms. In the ‘old days’, it all was blazingly fast.

Thanks for looking into it.

BTW, how can I find out what ‘worker’ is waiting on? Any hints?

BTW, Tried with Arc browser just now: 6s from reload to rendered page.

Did you have the Bear Notes integration installed back then, too?

As a matter of fact, yes.

I implied your suggestion and deactivated all extensions, to no avail.

Could you share a recording of the behavior with the notebook visible and the network tab and JS console open (please set it show all levels, including verbose)?

Do you mean a screen recording?

Also, I don’t know how to make two tabs (both Network and Console) visible at the same time.

Share my screen, maybe?

You can toggle the console with Escape (you may need to tap it twice the first time).

Here is an example layout that shows the notebook, network tab sorted by time descending, and the console with all log levels:

Note that for the notebook we only need to see when the UI loads, and when the notebook contents.

Wow. Learned something again. Thanks.

Here you go.

Did you mean to post a screenshot instead of a video? :slight_smile: (also, please sort the network tab by Time descending)

I was not sure. I now assume you want a video. I’ve prepped one. It’s 47MB. You can pick it up from WeTransfer - Send Large Files & Share Photos Online - Up to 2GB Free

Thanks! And do you only see this happen on your own notebooks? And only while you’re logged in or also logged out?

I see this on my notebooks (haven’t tested it on others yet), while logged in, logged out, and anonymous (private window). Also happens when logged in as other user (on same system).

In the log, I see two (Observable) workers, each waiting for 10 seconds.

My internet speed is ↓ 111.0 Mbit/s ↑ 33.0 Mbit/s.

Could you share the HAR file with me as well ( I’d like to take a look at the response headers.

And could you verify that you see the same issue in notebooks from other workspaces?

And does it happen in Chrome or Firefox, too?

Chrome and FF: all done in ~3s, albeit a bit jaggy; no smooth experience.

It strengthens my suspicion towards Apple.