Instagram is growing faster than Twitter, Facebook, and Pinterest combined

Instagram may need to introduce a new filter: white-hot. The photo-sharing app showed strong growth in 2013, according to a report by Global Web Index.

While Facebook showed -3-percent growth in active users, the behemoth social network's photo-sharing sister service gained 23 percent in active users. Reddit is the second-fastest growing social site, with a 13-percent increase, followed by LinkedIn at 9 percent.

Global Wed Index, which is an international marketing research firm, based these numbers on a survey they took from 170,000 users in 32 countries, TechCrunch reported. China was not surveyed, since the firewall presents problems in accessing social Web services, but its Sina Weibo still showed 6-percent growth - quite impressive considering the country it is based in did not participate. Additionally, Tencent Weibo, the Chinese Twitter to Sina Weibo's Facebook, showed an even bigger increase, nabbing a 9-percent hike in users despite the lack of Chinese participation.

Besides underlining Instagram's continued success, this report may cheer on Facebook fans worried about reports that the company is in a major decline. Yes, it did lose active users. But the report makes it clear that Facebook is still on top:

'Facebook remains the number one social network, topping the list for account ownership (83 percent), active usage (49 percent) and visit frequency (56 percent of users log in more than once a day). It is also the most popular site in all regions and its users are the most likely to be carrying out a range of networking activities.'

Also, let's not forget that Facebook owns Instagram, so a gain in users for the photo-sharing service is really just a win for Facebook under a different name.

The report also highlighted the increasing importance of mobile, and Facebook didn't come out so bad there, either: Facebook's primary app is the most popular social mobile app, plus its standalone messaging app, Messenger, is the fourth most popular. Instagram is eighth, so altogether, Facebook continues to dominate mobile apps.

Of course, give it time: Unless Facebook does a better job at courting younger users, these numbers may change dramatically.