Total Blocking Time
What is the Total Blocking Time parameter?
Speed performance
What is the Total Blocking Time parameter?
When a user opens a page of your website, there is a certain amount of loading time spent by the browser to show it fully.
This happens due to various reasons, each one monitored by a specific parameter.
The Total Blocking Time measures in milliseconds the timing between the occurrence of the First Contentful Paint and the Time to Interactive, if it exceeds 50ms.
In other words: if during loading (the period between FCP and TTI) a task lasts more than 50 ms, it is considered a long task; adding all the long tasks together you will have what is called the "blocking portion". The Total Blocking Time indicates the duration of the blocking portion.
For instance, if your result is an 80 ms of long task, the blocking portion will be 30 ms.
How SeoChecker determines the Total Blocking Time score
The score is assigned according to a ratio between the Total Blocking Time of your page and the Total Blocking Time data of a big archive of other websites (HTTP Archive).
In this table you can check the score parameters:
| TBT time (in milliseconds) |
Color-coding |
| 0 - 200 |
Green (fast) |
| 200 - 600 |
Orange (moderate) |
| > 600 |
Red (slow) |
How can I improve the Total Blocking Time of my page?
There are a lot of reasons why your Total Blocking Time can result slow; here are a couple of them:
- a not necessary JavaScript parsing, execution or loading;
- a not efficient JavaScript statement.