Script Lister
Lists external scripts and whether each uses async or defer.
Reading the result
Blocking scripts in the head can delay rendering.
Limitations
Reads one page as raw HTML, so anything added by JavaScript is not seen.
Example
Enter example.co.uk and run the check. The report opens when the check finishes.
Questions
What does the Script Lister do?
Lists external scripts and whether each uses async or defer.
How should I read the result?
Blocking scripts in the head can delay rendering.
What can it not tell me?
Reads one page as raw HTML, so anything added by JavaScript is not seen.