Conversion of pcapng files to txt file format

Unless the dump file generated by PCAP Next Generation (.pcapng) is a text based format, it is unlikely you can somehow convert or export it as a .txt file, with some kind of pcapng to txt conversion. You can always try to open it using notepad or other text editor and see for yourself, but you would have to find the text part manually - if there is such thing inside the file.

Open PCAPNG file    Open TXT file

Related software

Wireshark

A multiplatform network protocol analyzer