Customers can now see at a glance the latest Food Standard Agency (FSA) hygiene information for more than 30,000 restaurants and takeaways.
Food safety chiefs welcomed the ground-breaking initiative and called for other food delivery businesses to follow their example.
The move follows a trial in Northern Ireland where the ratings for over 600 restaurants were displayed on the Just Eat app and website.
Earlier this year the company launched a #1million scheme to provide training programmes to improve standards in restaurants with ratings of three out of five or less.
FSA Chairman Heather Hancock said: “I am pleased to see Just Eat taking the lead by making this positive step to publish the food hygiene ratings for businesses on their website.
“Having this transparency allows consumers to consider food safety when choosing to order food online and will help drive up standards across the sector. I encourage others in the sector to follow suit.”
Kate Thompson, Wales Director of the Chartered Institute of Environmental Health, said: “This latest announcement by Just Eat is excellent news.
“More and more consumers are choosing to use online food delivery platforms. The availability of food hygiene ratings at the point of ordering will enable them to make informed decisions about where they purchase their food.
“We would like to see others follow Just Eat’s example.”
While it is currently not compulsory for restaurants and takeaways to display their Food Hygiene Rating online, a Just Eat spokesman said the new initiative provided peace of mind for customers and incentivized restaurants to improve standards.
The company also commissioned research of 2,081 British adults which revealed that 93% of people believe it should be mandatory for food businesses to provide online access to hygiene information.
Eight in ten respondents said they considered it important to know the Food Hygiene Rating of a food business before they purchased food from them.
Just Eat’s UK Managing Director Graham Corfield said: “We spoke to customers about the information they want before choosing their takeaway, and their feedback was clear. They want easy access to independent information about the hygiene standards of their local restaurants and we’ve worked hard to make that a reality.
“This will have the dual benefit of giving customers all the information they want, while also incentivizing restaurants to invest in food hygiene and safety and ultimately drive standards up across the whole industry – even when the food isn’t being ordered via us.
“Our customers ordered more than 120 million meals via Just Eat last year and they deserve to have as much information as possible before making their food decisions.”