Signal said on Saturday it had restored its services a day after the application faced technical difficulties as it dealt with a flood of new users after rival messaging app WhatsApp announced a controversial change in privacy terms.
Signal has seen a rise in downloads following a change in WhatsApp's privacy terms, which required WhatsApp users to share their data with both Facebook Inc and Instagram.
Signal users might see errors in some chats as a side effect to the outage, but will be resolved in the next update of the app, the company said.
The error does not affect the security of the chat, the company added.
The non-profit Signal Foundation based in Silicon Valley, which currently oversees the app, was launched in February 2018 with Brian Acton, who co-founded WhatsApp before selling it to Facebook, providing initial funding of $50 million.