Website image optimization can negatively impact user experience, according to a new report from Radware titled, “Progressive Image Rendering: Good or Evil?”
The report reveals that poor image optimization on web pages has a clear measurable impact on the user experience.
Radware commissioned NeuroStrata, a leader in neuroscientific research, to test three different image renderings. Using facial analysis software, moment-by-moment emotional responses in universal facial expressions of more than 250 participants were captured as they were presented with three randomly selected image formats on a web page and were asked to complete tasks that relied on either textual or visual cues. Test subjects were also surveyed about their attitudes and expectations with regard to online images.
Here are some key findings from the report:
- Default image formats, used by up to 95% of all websites, do not deliver the highest level of user satisfaction
- 65% of participants have felt frustrated by images taking too long to load
- 51% of participants wait for most or all of a page’s images to load before they begin to interact with the page
- 50% of participants feel that the way in which images load has an effect on their web browsing experience.
Typical web pages use two of the three image formats used in the study – a standard lossless GIF file and progressive JPEG. The third image file used was a newly developed file, using a proprietary rendering format not yet available to the public. In the report, this new rendering technique was clearly favored by those who were tested compared to the two typical formats.
“Humans are extremely visual,” Tammy Everts, performance evangelist for Radware, said in the report. “Imagery grabs our attention, evokes a response and sustains our emotional engagement. As images comprise over 50% of the weight for a typical web page, this neuroscientific study shows that serving images faster on your website does have a direct and measurable impact on the user experience.”