WebPagetest VS Blackfire.io

Trust neither. The most optimal option I've found is webpagetest.org Its been quite handy lately. This tool does look interesting. Source: about 1 year ago

Webpagetest.org is another. Pagespeedinsights and lighthouse are great for identifying page load issues to fix, but actual page load times will always vary between the user and your web server. Universal analytics has some page load timings but that's going away soon and nothing afaik is in GA4. I've seen an example of building a page load timer in tag manager and dumping the results into an event. Source: about 1 year ago

So I am working on rebuilding our company's site with a new stack. I am running tests using webpagetest.org, and I am having trouble fully understanding the speed index results as well as the film strip view. The page renders quite fast everywhere I test it. Google Lighthouse shows it in the 90s + for performance score, however when I test the page on webpagetest, I get load times of 77 seconds (NOT MS) which is... Source: about 1 year ago

Webpagetest.org is great, and checking OP's site they have done an incredible job, I don't think I have ever made or seen an Ecom site this slick. Super clean waterfall view. Source: about 1 year ago

Thanks for the recommendation regarding webpagetest.org, another user made a similar recommendation so I will check it out. Source: over 1 year ago

Not heard of blackfire.io, I mainly use lighthouse, screamingfrog and CRUX data :D. Source: about 1 year ago

Do you have XP with alternatives to blackfire.io? It may helps, but sounds a little expensive for evaluating performance issues. I found also MySQLTuner which is free (of course it only helps with the database). Source: over 1 year ago

Go get a subscription to blackfire.io and profile your application. I guarantee you that your queries to the DB are shit and not using indices. Redis will just mask the issue. You probably also have a bunch of PHP code being ran in loops. Source: over 1 year ago

Although the connection with the API should no longer cause the trouble, we knew that this was the most compute-heavy part of the platform. So the fewer requests are sent to that API, the better the website performance would be. We used Blackfire.io to check how often the web app uses the API and we got interesting results. We noticed that the homepage, the most frequently visited page, used the API twice per each... - Source: dev.to / almost 2 years ago

Nice article; skimming over it, it seems exhaustive and well-written. But nowadays, I'd generally recommend blackfire.io over XHProf. Yes, it's a (mostly) closed source SAAS platform, and the free tier only offers the most absolutely basic of tools, but by the time performance really starts to matter on your wordpress site, I don't think ~$30 a month is a dealbreaker. Installation is easier, the visualisation... Source: almost 2 years ago