Why there is no option to combine JS files?
FlyingPress doesn't provide an option to combine/contact JavaScript files. This is intentional, for performance!
- With http/2, combining is not recommended. Browser doesn't have to wait and parse a large file. Smaller files are better.
- Combining will result in lower cache hit ratio in both browser cache and CDN cache. This is because whenever a single file is updated, the whole JS file needs to be downloaded again. When not combined, only the file changed will be downloaded.
- This can dramatically increase cache size, cache build time and increased resource usage in your server.
- Every time we purge, it encourages chances of another 404 for Search Engine crawlers.
Google PageSpeed Insights will never show a recommendation to combine JavaScript files. GTmetrix also removed this recommendation in April 2020.
Few resources: