According to Wikipedia, the brothers Mike and Chris Whyley developed Zamzar in the United Kingdom and launched it in January 2006.
Zamzar "allows users to convert files without downloading a software tool, and supports over 1,200 different conversion types" (Wikipedia, 2019).
On Zamzar's website this tool is described as a "free online video converter, audio converter, image converter, eBook converter. No download or account required."
Examples of Zamzar's popular conversions:
PDF to Word PDF to Excel
FLAC to MP3 DOC to PDF
EPUB to PDF MP4 to MP3
PDF to DOC WAV to MP3
MOV to MP4 Excel to PDF
PNG to PDF PDF to JPG
DOCX to PDF EPUB to MOBI
MP3 to WAV MP4 to GIF
PPT to PDF PNG to JPG
PDF to DWG PDF to DOCX
FLV to MP4 Word to PDF
Zamzar's website:
https://www.zamzar.com
Zamzar described on Wikipedia:
https://en.wikipedia.org/wiki/Zamzar