The development reflects the growing popularity of digital platforms among children and teenagers.
Elle Girl had a circulation of around 600,000 in print compared with an online readership of 3.8 million page views and 500,000 visitor sessions each month. The ELLEgirl.com email newsletter has 80,000 subscribers. Around 90 per cent of online content is unique to the site.
Thirty staff are expected to lose their jobs with the closure of the print magazine's last edition in June/July.
Hachette Filipacchi Media CEO Jack Kliger told the New York Post that the site would: "work on ELLEgirl ringtones, wallpaper mobile pages and projects in the mobile blogging area".
"When teen girls are not on the web, they are on their cells," he said.
The UK version of Elle Girl was closed by publishers Hachette Filipacchi UK last year, but the magazine did not have an online edition.
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