Wifi speed is slow, ethernet is over 100 wifi is 20

Ethernet is fixed speed.. wireless speed depends on range, path loss, signal level of bands, humidity of this moon phase and other voodoo factors.

Wireless will never match ethernet ever.. if you want faster speeds you must tell us all..

What computer, what wifi router, what standards you are connect to, what band.. what link speed.

Please run the apple diagnostics if this is an apple computer.. we don't even know that.

Use Wireless Diagnostics to help you resolve Wi-Fi issues on your Mac - Apple Support