The following are the difference between inline JavaScript and external file −
External scripts
- The browser stores the external script once it is downloaded for the first time. If it is to be referenced again, then no additional download is needed.
- This reduces download time and size.
- The async and defer attributes have an effect. If these attributes are present the script will change the default behavior.
Inline scripts
- Inline Scripts are executed immediately.
- It gets loaded instantly and there is no need to trigger another request.
- The async and defer attributes has no effect.
- Inline Scripts are more useful for server-side dynamic rendering.