Google chief executive Sundar Pichai has said a censored search app in China could serve over "99% of queries," in rare public comments about the controversial proposal.
Mr Pichai told a conference in San Francisco the plan was in the "very early" stages and may not progress.
Google's possible return to China – a market it abandoned over censorship concerns – was first leaked in August.
The proposal has drawn criticism from employees and human rights advocates.
On Monday, Mr Pichai did not commit to the launch, saying that the plan was still in an exploratory stage.
"We wanted to learn what it would look like if Google were in China, so that's what we built internally," Mr Pichai said at the Wired conference in San Francisco.
"It's very early, we don't know whether we would or could do this in China but we felt like it was important for us to explore. I think it's important for us given how important the market is and how many users there are," he said.
Through internal tests, he said Google found it would be able serve "well over 99% of queries".
Pichai on China:
– says the firm never really left China anyway
– “99%” of searches would still get through
– taking long term view
Goes without saying – that 1% contains an awful lot.
— Dave Lee (@DaveLeeBBC) October 16, 2018
End of Twitter post by @DaveLeeBBC
The firm, which is owned by Alphabet, quit China eight years ago in protest at the country's censorship laws and alleged government hacks.
However, reports in August claimed it had been secretively working on a new Chinese search service, referred to internally as Dragonfly.
The platform, which still requires Chinese government approval, would reportedly block certain websites and search terms related to human rights and religion.
This has angered some employees who fear they have been unwittingly working on technology that will help China suppress free expression.
Earlier this month, US Vice-President Mike Pence called for Google to immediately halt work on Dragonfly, saying in a speech that it would "strengthen Communist Party censorship and compromise the privacy of Chinese customers".