|resources:||Home Mailing List Installation Source Code Members Screenshots|
- News item goes here
- More news items go here
- stuff goes here
- more stuff goes here
For a given page,
- track how long it takes to see the first byte from remote server (time-to-first-byte (TTFB)).
- track how long it takes to complete displaying the page (time-to-completion (TTC)
- track the page size
- track number of sub-requests used to build the page
- sample display (browser's lower-right-hand corner):
Once the extension is installed, each time you access a page, you will see the lower right status bar get updated at completion time to include information about
- TTFB: how long it took to see the first byte from remote server (from click to first byte received). This value gives a rough estimate on when the browser can start laying out the content.
- TTC: how long it took to display the page (from click to complete drawing of the page)
- Page size (number of bytes used to display the page): this value includes both bytes fetched from network and bytes fetched from the browser's cache.
Notes: that the above stat is only updated when a page is completely displayed (the progress bar is no longer displayed).
Some rule-of-thumbs on how to interpret/compare these metrics:
- For TTFB, shorter is better. Even for page that is large, a short TTFB (less then .5 sec) allows the browser opportunity to layout the page content as soon as possible. This can enhance the user's perception of responsiveness.
- TTC, obviously shorter is better. The current general agreement is that anything above the range of 7-10 seconds are perceived by user as slow.
- Page size, smaller is better. Most fast sites seem to max out around 75KB per page. Anything above 100KB tends to appear sluggish.
- Number of requests, smaller is better. Nowaday, with HTTP persitent widely supported, the cost of fetching another request no longer significant. But keep an eye for extreme cases (50+). This value tends to correlates well with the page size (large number of request -> large page size).
Note: If you want to add an area for user feedback to any of your pages, take a look at the notes.html template.