42 votes
Accepted

How to improve extremely slow page load time on a 23MB web page full of SVGs?

From what you've stated in the comments (now chat), I understand that you cannot reduce the size of these SVG files, you cannot replace them with thumbnails (e.g. small png files), and you cannot ...
Maximillian Laumeister's user avatar
24 votes

How to improve extremely slow page load time on a 23MB web page full of SVGs?

I don't think using separate SVG files for the images would be any better because that would take even more time to load because of separate HTTP requests. Efficient handling of linked images is ...
Boann's user avatar
  • 341
13 votes

How to test the speed of a page that is guarded behind login page?

2020 update The Lighthouse tool is now part of Chrome, and you can access it from Developer Tools (F12) -> Audit. You can use it on logged-in pages, and even against Chrome on a real mobile device (...
Dan Dascalescu's user avatar
11 votes
Accepted

When should I use the “crossorigin” attribute on a “preconnect” <link>?

All the answers so far seem either simplified, incomplete or partially wrong (topic is complex, things are confusingly named and not well documented!), so here's my understanding: To be able to reuse ...
jakub.g's user avatar
  • 286
11 votes
Accepted

Blank image. What to use: Base64 vs 1x1 JPEG image

The base64 image option should be used where you would only have a very small number of images and you want to eliminate the network overhead of fetching a picture from the server. However from what ...
Chris Rutherfurd's user avatar
11 votes

How to optimize the load time of initial connection and SSL handshake phase of a web page on a 3G network?

Initial Connection You will find that the initial connection includes negotiating the SSL, so since the handshake is high, its a good indicator that something is seriously wrong with the way you have ...
Simon Hayter's user avatar
9 votes

Performance: 4096 Bit RSA-Key compared to 2048 bit RSA-Key

Use OpenSSL's speed command to benchmark the two types and compare results. Here's an example command to run on the server to compare only the key types and sizes you mention: openssl speed rsa2048 ...
Tom Brossman's user avatar
  • 2,291
9 votes
Accepted

Speed comparison - absolute vs relative path links

Effect for browser: Though this looks like a bit of work for web browser, but technically it does not make much of a difference. The browsers are too fast to handle these relative url structure and ...
abhinsit's user avatar
  • 1,714
8 votes

How to optimize the load time of initial connection and SSL handshake phase of a web page on a 3G network?

Reading the title of your question, there are two things you can do to speed up the initial connection and SSL/TLS handshake. These work for any connection, not just 3G, so you should use these as ...
Tom Brossman's user avatar
  • 2,291
7 votes

When should I use the “crossorigin” attribute on a “preconnect” <link>?

I was searching for the same thing and I found this It states here that if you don't use cross origin attribute the user agent just does the dns lookup but doesn't establish connection with the ...
orangespark's user avatar
6 votes

What is an acceptable "Time spent downloading a page (in milliseconds)" in Google Search Console?

That report shows how much time Googlebot spends downloading each page on your site, not including linked resources such as JS, CSS, iframes, and images. It is less important to optimize your ...
Stephen Ostermiller's user avatar
6 votes
Accepted

How do I add the an expires header for external URL components as suggested by GTmetrix and YSlow?

As @Evgeniy has already covered in his answer, in order to add HTTP response headers to resources external to your site, you need to copy these resources locally - to a server that you control - so ...
MrWhite's user avatar
  • 42.8k
6 votes
Accepted

Use A.jpg if you have it in cache, otherwise use B.jpg?

TL;DR answer: I don't think that exists in the way you mentioned similar to webp and, if it's possible, it would be with messy/unsupported workarounds. It may even trigger some ad blockers / antivirus....
Trich's user avatar
  • 601
5 votes

Performance: 4096 Bit RSA-Key compared to 2048 bit RSA-Key

I decided to run openssl speed with three key sizes: 1024, 2048 and 4096 bits. Here are the results on my home PC, which is decent but far from exceptional as far as number-crunching power goes: ...
user's user avatar
  • 351
5 votes

Blank image. What to use: Base64 vs 1x1 JPEG image

Definitely go with the data URI, unless you need support for IE < 8. (Browser support.) Embedding lots of tiny images directly in the HTML may look like it will take up more bandwidth than linking ...
user2428118's user avatar
5 votes

Can minifying the HTML of page have a negative effect on SEO?

This is a good question, but the answer is no - it will not affect your search engine rankings negatively. It will provide a (marginal) benefit due to decreased file size. To understand why it won't ...
Tim Malone's user avatar
  • 1,256
5 votes

Google Page Speed Insights is recommending inline styling and complaining about render blocking JS. Are these even relevant?

One of the Google guys, Paul Lewis, said achieving 85 or better should be your goal. Of course those things you mention matter. Both to Google and, especially, users! Page render blocking is ...
Rob's user avatar
  • 4,613
5 votes
Accepted

Is it faster to request a single 7KB file faster than to request 6 files totalling 7KB?

With HTTP/1, the answer is yes. As mentioned by Michael Hampton, combining files (which prefer I call "concatenation") is a typical web site performance optimization. This is due to overhead related ...
Andrew Myers's user avatar
5 votes

Parallelize downloads with one server by using apache

Yes, this is a perfectly valid solution to the problem. It also covers the "use a cookieless domain for static assets" speed recommendation, if setup correctly. This won't add additional server load, ...
Tim Fountain's user avatar
  • 4,454
5 votes

If I change a Wordpress Theme then will it result in Performance and Page Loading Speed Improvements?

Always Look for Better Solutions As a rule-of-thumb, always look to see if there are any better solutions. Themes often become dated or even abanded when the developers move on or focus on a new ...
Electron's user avatar
  • 314
5 votes
Accepted

Why pay for a distributed DNS service when ISPs cache lookups?

You shouldn't host DNS in your basement. At a minimum you should have 3 DNS servers located in different geographic locations on separate networks. Otherwise DNS is a single point of failure. Your ...
Stephen Ostermiller's user avatar
5 votes
Accepted

How do you serve Jekyll pages with gzip compression on GitLab Pages?

GitLab Pages will serve pre-compressed .gz files that exist alongside uncompressed equivalents. A general solution that should work with most static publishing systems is to put this as the last step ...
Daphne Preston-Kendal's user avatar
5 votes

Should I dns-prefetch all Google Ads domains?

I wouldn't bother preloading DNS for Google Analytics or ads. As Simon mentioned, ads are generally loaded with lower priority than the rest of the content anyway, so it's not like they would be ...
Maximillian Laumeister's user avatar
5 votes
Accepted

Does having a lot of 301 redirects noticably impact performance?

will having almost 1000 redirects in the .htaccess file significantly slow performance Having 1000 separate redirect directives in .htaccess could certainly impact performance, although that may not ...
MrWhite's user avatar
  • 42.8k
5 votes
Accepted

Why would Google Analytics report slow loading times when other website testing tools show it is very fast?

The average page load time in Analytics shows actual user experience data based on network, server, and browser time for multiple visitors. For example, if you are receiving traffic from Zambia (which ...
Emirodgar's user avatar
  • 3,817
4 votes

What is recommended minimum object size for gzip performance benefits?

Apache Tomcat has gzip filter and it starts to zip from 2kb, my quick test tells that it's the lowest boundary, and you can increase it at least to 3-4kb. Because for 2kb you will get a similar size ...
Yura's user avatar
  • 141
4 votes

Is gzip compression available for GitHub pages?

besides Dan's answer, depending on your static-site generators, there can be some plugins that make the compressed .gz-ed version offline while generating the site. By that way, your server can serve ...
kmonsoor's user avatar
  • 141
4 votes
Accepted

Do sites without ads perform better in Google search results?

Google will penalize pages with an excessive number of ads but you can have up to three ad blocks with no penalty (based on AdSense policy). As for page load it does effect pagerank but not a ...
Chris Rutherfurd's user avatar
4 votes
Accepted

Google Pagespeed asks to eliminate "above the fold" files that are required for the page to render

Waste of time... more often than not... insight... not required. Matrix's and Google's Pagespeed Insights is not mandatory and will not reward you with any secret squirrel level 9 Google rankings. ...
Simon Hayter's user avatar
4 votes

Can we improve site speed for Googlebot by directing it to its own dedicated server?

Showing bots better performance won't help SEO. If that is what you hope to gain from it, it won't work. Google's algorithms for slow sites only punish really slow sites. Ones that take 7+ ...
Stephen Ostermiller's user avatar

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