He retired from Wheelock on 31 March 1998 at the age of 32 and in the same year, founded Webb-site.com, a non-profit platform to advocate better corporate and economic governance in Hong Kong.

[13] Since 1998, Webb has built and maintained an extensive and rigorous set of Hong Kong public data records, at his eponymous Webb-site.com, which he synthesises and cross-references in a highly accessible format, in pursuit of transparency.

[14] Information includes datasets and analyses for multiple aspects of: financial, securities, stock market data, directors and boards; government accounts, utilities and economic issues; members of judiciary, advisory and statutory bodies; SFC licensees, solicitors and other professionals; vehicle and traffic data; and notable people in all aspects of Hong Kong life.

[15] Webb has been referred to as the "'Long Hair' of the financial markets" (in an allusion to Leung Kwok-hung), as his activism initially concerned mainly the finance sector.

[11] In December 2005, he advocated widening the electorate of the functional constituencies, arguing that professionals in fields such as bankers and stockbrokers should get to elect their own representatives.

[17] He observed then that only accountants, lawyers, doctors and teachers are able to exercise that right;[17] stockbrokers are represented by convicted fraudster Chim Pui-chung,[18] whilst the banking seat has only been contested once in 20 years.

[22] Webb remarked that the government was the second-largest single investor in the Hong Kong market after Beijing, with a portfolio of local equities estimated to be worth about HK$150 billion.

In 2005, Webb criticised the government for its lack of accountability, through its refusal to uphold a promise of independent directors on the board of Hong Kong Disneyland.

In February 2025, with the prospect of his death imminent, and after unsuccessfully seeking ways to continue the site without him, Webb announced a phased closure of record maintenance.