[6][7] Sleipnir was originally created in Japanese and then released with English and Chinese translations.

Early Gecko-based versions of Sleipnir for Windows scored positive reviews from CNET for the design and functionality, most noticeably, for the inclusion of gestures.

“The action is very smooth and natural and a lot like scrolling through pages on your phone with your thumb.”[24] The OSX version review by MakeUseOf followed generally the same line while additionally bringing attention to the convenient tab management.

[25] MacWorld, while reviewing Sleipnir 4 for Mac has praised how the URL bar was changed.

“Opera pioneered that idea, but Sleipnir’s tabs remain constantly visible and strike a nice balance between being large enough to identify but small enough not to intrude on the main browser window.” Despite this, version 4 was criticized for its poor performance, compared to other browsers using WebKit.

“Sleipnir proves to be a stable and fast web browser that comes with innovative functions and various customization possibilities.

The extra security features, together with smartphone and web apps linking are features that make it a viable alternative to its more popular competitors.”[27] In 2012, multiple performance tests were performed by Tom's Hardware, where the Android version of Sleipnir was placed on the third spot as the best browser for Android, outrun by Dolphin and Maxthon.