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 ...
- 15.6k
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 ...
- 341
12
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 (...
- 350
12
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 ...
- 10.2k
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 ...
- 286
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 ...
- 32.9k
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 ...
- 2,271
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 ...
- 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 ...
- 2,271
7
votes
Tradeoffs around using a query string vs embedding version number in the CSS/JS files
Just to clarify, since it's not explicitly mentioned in the question, that the reason for doing this in the first place is to break the client cache (aka "Cache Busting")...
As far as I know ...
- 42.6k
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 ...
- 171
6
votes
Accepted
Can rewriterules work without carets or dollar signs?
You are using the ^ and $ (anchors in regex speak) because you are matching the whole URL, which is what most people want to do, so this is the most common example you see.
If you omit the ^ and/or $ ...
- 42.6k
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 ...
- 97.8k
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 ...
- 42.6k
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....
- 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:
...
- 351
5
votes
Confused about missing width and/or height attributes
Adding the height and width attributes to your IMG SRC HTML tag allows
the browser to know how much space to leave for an image. Without
these values, the browser gives an image no space until the ...
- 2,486
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 ...
- 696
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 ...
- 1,266
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 ...
- 4,623
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 ...
- 251
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, ...
- 4,444
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 ...
- 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 ...
- 97.8k
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 ...
- 191
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 ...
- 15.6k
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 ...
- 42.6k
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 ...
- 3,807
4
votes
Confused about missing width and/or height attributes
The browser requests this for performance. Say you have a paragraph of text with an image of 100x100 pixels in the top left corner.
Browser builds the page, no image yet, so it builds it with just ...
- 6,826
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 ...
- 141
Only top scored, non community-wiki answers of a minimum length are eligible