How to evaluate a blog – Part 6: Speed
The download speed of the home page, and the individual pages on a blog are important. Internet users are an impatient bunch. Even if they have a good Internet connection, people will not wait for a page to download for more than 30 seconds. Often we forget not everyone uses high-speed connections. Pages of 1 Mbyte are a bitch to download over anything less than an ADSL link, and will chase people away faster than we can attract them to our blog. No matter how good our content is, if a blog is slow, it won’t be successful.
Beyond the relation between usability and speed: Search engines started to penalize slow sites by ranking them lower.
So, in short: the blog speed analysis is a key element in the evaluation of a blog.
While evaluating the speed of a website, I use Mozilla Firefox with two plug-ins:
- “Firebug” allows me to analyse in depth the size and download speed for the different parts of a page:
- “Google Page Speed” gives me a generic overview of the main issues, and gives tips how to improve them:
While I wrote before about basic principles to speed up a blog, here are the common issues to look at:
- How fast does the home page, and the individual blog page load? Anything more than 30 seconds on an ADSL line, is a no-go.
- What is the actual size (in Mbytes) of the home page, and the individual pages? Keep them below 0.5 Mbyte, for sure!
- Are pictures properly compressed? Most of the blogs which are slow, don’t compress pictures.
- Are pictures actually displayed at their true dimensions, or are are they resized on the fly? Avoid on-the-fly resizing, it is a waste of resources!
- Is there any way we can optimize the most commonly used image elements (like the banner, icons, etc…) which appear on most pages?
- Are the dimensions (the “width” and “height” attributes) defined for all pictures? This helps a browser calculate the position for each picture much faster.
- Are there any image elements stored on external servers, which might slow down the page? This is a typical problem I found for social media bookmarking icons, or the “Creative Commons” logo… It is often worthwhile storing these on the blog’s own server
- Any way to group sets of icons into one picture or splice rather than displaying them individually?
- Are all image elements stored on the same domain? Most if the time, it is worth while to store the static elements (icons, background images, header images) on an external server, and the dynamic elements on the blog’s server. This way, the browser can load them in parallel
- Does the blog use a cache, and does it use the cache used properly? Do they pre-cache pages?
- Do they use page compression? They should!
- Do they leverage browser caching for static content (icons, style elements, scripts,..) ? Static content such as CSS and icons should have a long cache lifetime
- Are there any widgets or plugins slowing down the blog? Many bloggers love to include plenty of widgets, but the more widgets, the slower the blog. I have seen a frequent problem with carousels of Flickr pictures, or ‘most recent videos’ and ‘subscriber’ thumbnail widgets, which all use resources from an external server. Often, those resources are overloaded, and 90% of the time, they will slow down your blog. A simple remedy is to display a static picture of that widget, and make it click-able so the visitor still gets the functionality as before, but without the dependency of the external server speed.
In the next part of our blog evaluation series, we will look at SEO or Search engine optimization.