PSI doesn't support HTTP/2 (H2)

[snake-345]

I was trying increase performance of our sites and found some strange thing. When I bundled our js files pagespeed had given me better results, but is strange, because our site working on http2 and this protocol should working better with many small files then with one bundled file.

I checked our graylog and what I saw:

As you can see all requests is Http1. Why?

Links:
Our sute
Checking http2 support

[connorjclark]

For the time being, PSI does not support h2. We even currently disable an audit that specifically checks for h2.

@patrickhulce think we should add this source of variability between channels in the variability docs?

@kusler Maybe we could add a disclaimer about h2 support in PSI somewhere?

There's currently no timeframe for support, but I've just knocked on the appropriate team's inbox to get an update.

Internal to googlers: b/32022322

[snake-345]

Holy cow. I can't believe it.
Could it be reason why Google chrome lighthouse give better score then pagespeed insights?
Does it mean that we have to bundle our files if we wanna good score in pagespeed insights?

[cheneytsai]

Here's a test page: https://www.babycenter.com/0_signs-of-labor_181.bc

I get vastly different results on PSI/web.dev (6-7 range) vs. running locally or on WPT ( 45-55 range) in a consistent fashion. They make heavy usage of h2 multiplexing, and I was wondering if PSI not supporting H2 is causing the difference here.

[cheneytsai]

@patrickhulce bump on whether this is documented anywhere? thanks!

[exterkamp]

@patrickhulce bump on whether this is documented anywhere? thanks!

Definite opportunity for some PSI docs. @paulirish do we have/want to make a PSI FAQ? This would definitely make it on there.

[ScottTravisHartley]

Can I get a clarification on the reason Page Speed Insights doesn't appear to support HTTP 2 even though 90% of internet browsers actively support it?

https://caniuse.com/#feat=http2

This kind of blows my mind a bit lol.

[bourds]

Is there any update on a timeline for this fix to enable HTTP/2 support in PSI? It feels a bit awkward that running Lighthouse directly gives you a different performance score than the one you get when running PSI. Especially since the PSI result page clearly indicates that "The speed score is based on the lab data analyzed by Lighthouse."

[connorjclark]

It feels a bit awkward that running Lighthouse directly gives you a different performance score than the one you get when running PSI.

yeah :(

I can confirm it's now on the roadmap!

[juliquiron]

I can confirm it's now on the roadmap!

Great news! sites relaying on http2 multiplex using granular assets will not be penalized more. Also usging http2 push feature properly increases the performance and should be also audited. Thanks.

[litvinovvo]

I can confirm it's now on the roadmap!

Great news! sites relaying on http2 multiplex using granular assets will not be penalized more. Also usging http2 push feature properly increases the performance and should be also audited. Thanks.

Great to see that Lighthouse is supporting this feature now, have we any updates about HTTP2 support from the PSI?

[connorjclark]

nope. hit the subscribe button, I'll comment on this thread when there's something to update.

[filrak]

I will be also very interested in knowing about this support for PSI. It's hard to convince clients that low scores are because of lack of HTTP/2 support ;)

[connorjclark]

We just deployed a new version of Lighthouse to PSI and there was a bug. We intend to skip that audit in PSI for now, atm it is only being skipped for desktop runs in PSI. We're working on a fix.

[connorjclark]

It's properly skipped now.

[connorjclark]

Alrighty, as of this afternoon h2 is now working in PSI. We saw a good number of perf score increases across the board. At the median, it was about 6 or so.

https://developers.google.com/speed/docs/insights/release_notes?hl=en-US&utm_source=PSI&utm_medium=incoming-link&utm_campaign=PSI#march-3,-2021

[anxgstadler]

Do we have to wait a bit until the changes will take effect?

I'm running PSI on https://www.der-schweighofer.at/
Firefox and Chrome both use H2 to download assets, external services confirm that HTTP/2 works.
PSI still uses HTTP/1.1 and recommends switching to H2. Why?

(I'm using PSI from Austria, if this makes any difference.)

[connorjclark]

Yea, I can confirm we're only loading that host with http/1.1.

I'm using PSI from Austria, if this makes any difference

I'm not sure why, but it's not this since I see the same problem from the US. Do you know where the server is hosted?

[Teddielike]

Yea, I can confirm we're only loading that host with http/1.1.

I'm using PSI from Austria, if this makes any difference

I'm not sure why, but it's not this since I see the same problem from the US. Do you know where the server is hosted?

Only if the server supports tls 1.3.
I just had the same mistake after the activation.

[anxgstadler]

Thanks for your replies.
We are hosting the servers ourselves; TLS 1.3 and 1.2 are enabled, older versions are disabled.

[alxtv]

Do we have to wait a bit until the changes will take effect?

I'm running PSI on https://www.der-schweighofer.at/
Firefox and Chrome both use H2 to download assets, external services confirm that HTTP/2 works.
PSI still uses HTTP/1.1 and recommends switching to H2. Why?

(I'm using PSI from Austria, if this makes any difference.)

It's the same for me - https://ls02.wpxtools.com/

[jkahrs]

Do we have to wait a bit until the changes will take effect?
I'm running PSI on https://www.der-schweighofer.at/
Firefox and Chrome both use H2 to download assets, external services confirm that HTTP/2 works.
PSI still uses HTTP/1.1 and recommends switching to H2. Why?
(I'm using PSI from Austria, if this makes any difference.)

It's the same for me - https://ls02.wpxtools.com/

Just for completeness: This server seems to be using TLS 1.2

I am getting the same at: https://test.datenspaten.de/ (also TLS 1.2) more interestingly: When I switch the website to an empty (default) Typo3 installation the HTTP2 warning seems to disappear again.

Update: https://test.datenspaten.de/test also tests as HTTP2 working

[Teddielike]

Just for completeness: This server seems to be using TLS 1.2

I am getting the same at: https://test.datenspaten.de/ (also TLS 1.2) more interestingly: When I switch the website to an empty (default) Typo3 installation the HTTP2 warning seems to disappear again.

That‘s an important information… i think the problem is with the Cipher Suites.

If I use your suites (ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-RSA-AES128-GCM-SHA256), I have the same problem. ❌

If I use more (ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES128-GCM-SHA256), it works. ✅

Update: https://test.datenspaten.de/test also tests as HTTP2 working
That is not right, the page contains nothing relevant, so this is not reported. (Same here: http://antemon.hu/phpinfo.php)

@connorjclark I don't think the tls 1.3 cipher suites (and other) are being supported.

[connorjclark]

Thanks for the reports, we're looking into it. If you could keep these URLs configured the same for at least a short while, it'll help us in debugging.

1. https://test.datenspaten.de
2. https://ls02.wpxtools.com/

[pt44]

Same issue here - site is http2 enabled, loads h2 when I check. The http2 error doesn't report in Chrome Lighthouse, only in PageSpeed Insights report.

https://tansleyphotography.co.uk/
WPX.net is the host

Noticed same with a friends site too. On Siteground UK. Something in PSI is either a/ reporting the error incorrectly b/ for some reason when it runs the site from its server, it's getting an http1.1 version.

[karlkowald]

Have the same problems with all pages hosted at our systems.
We use actual nginx with http2 support, if we check in dev-console in browser, resonse is always http2 and works correct.
running lighthouse at my local chrome it says http2 works correctly... using the online-Test from PSI it says we should use http2, cause its not working...

https://www.aurora-wp.at/ (one example)

[mannclann]

I also experience same issue. Browser clearly shows HTTP/2 yet PSI tells me HTTP/1.1 and showing an extra 1.5 - 2 second delay because of it. Considering Google is now going to use speed as a ranking factor this penalization (which is wrong to begin with) seems a bit unfair. Very frustrating.

[rsanzante]

Same problem here, PSI tells the server is using HTTP/1.1 (it reports the root address, like https://exmaple.com, but no other URLs). Browsers and curl report HTTP2.

I've checked TLS: the server uses TLS 1.2 or 1.3 (1.0 and 1.1 are disabled).

[pt44]

Update. I fixed my own website. I use WPX as my hosts. They have a custom built Cloud CDN. I turned it off, after seeing a comment on another forum. Fixed it. Http2 error goes away. PSI speed went from 94 to 99 instantly.

There is clearly something about how their CDN works and PSI and how it measures. The CDN was definitely delivering Http2, but PSI wasn't recognising it for whatever reason. As others on Siteground have the same problem, it clearly isn't just limited to one hosting company either.

[connorjclark]

It seems that any site using TLS 1.3 will result in PSI using http/1.1 to communicate instead of h2.

We have hidden the "Uses HTTP2" audit from PSI while we continue to work on a fix. In the meantime, the performance score of pages that use H2+TLS1.3 will be equivalent to before we added h2 support. For pages that use H2+TLS1.2, the improved scores will remain.

[alxtv]

https://ls02.wpxtools.com/ uses H2+TLS1.2 only and PSI is using http/1.1 to communicate instead of h2.

[dbloembe]

@connorjclark is there any update in PSI supporting H2+TLS1.3?