In November 2009, a British company called I-CD accused Popkov of copyright infringement, alleging that he used proprietary information from his previous employment to create a site similar to Passado, the project 192.com.

[6] In November 2009, after the first day of trial in the Royal Courts of Justice,[7] I-CD dropped all charges against Popkov and Odnoklassniki[8] after they agreed to pay an undisclosed amount as settlement.

[9] Paid registration was introduced in Odnoklassniki in 2008, but this led to a decline in popularity as users began migrating to the main competitor, VKontakte.

It was ranked fifth in terms of monthly reach among all Russian-language resources targeting internet users aged 14–55 in July 2009, according to TNS Web Index.

Odnoklassniki expanded its reach by providing localized versions in different languages, such as Azerbaijani, Uzbek, Armenian, German, Turkish, and Tajik.

The social network also faced challenges, such as being blocked by the Ukrainian government in retaliation for the annexation of Crimea and dealing with technical issues that temporarily affected site availability.

In recent years, Odnoklassniki continued to innovate with features like the "Recommendations" service, new emoticons beyond the "Class" button, a video feed on the mobile app, and an ad account for small businesses and content creators.

The platform also launched a portal called "We are in the museum," focusing on art-related content, and saw an increase in users following the blockage of Instagram in Russia.

In May 2017, Ukrainian President Petro Poroshenko signed a decree to impose a ban on Mail.ru and its widely used social networks including VKontakte and Odnoklassniki as part of its continued sanctions on Russia for its annexation of Crimea and involvement in the War in Donbass.

[38][39] The move was widely criticized as censorship, and Reporters Without Borders condemned the ban, calling it a "disproportionate measure that seriously undermines the Ukrainian people’s right to information and freedom of expression.

Transfers are made between MasterCard, Maestro, Visa payment cards issued by Russian banks and linked to user profiles.

Mauricio Garcia, perpetrator of the 2023 Allen, Texas outlet mall shooting, reportedly used his account on Odnoklassniki to promote white supremacist and neo-Nazi views, and in particular to target Asians.