The Latest E-commerce Site Speed Ranking for May 2025: Key Insights and Cases

EC Site Speed Ranking for May 2025

In an effort to enhance digital business performance, Gaprise Co., Ltd., a SaaS provider based in Tokyo, has unveiled its latest findings from the May 2025 speed ranking of domestic e-commerce sites. This evaluation examined the loading performance of sites belonging to the top 300 online retailers in Japan, as identified by the latest sales rankings.

Overview of the Research

Survey Period

The data reflects the state of e-commerce in May 2025, showcasing current site performances.

Research Agency

The research was conducted by Gaprise.

Research Subjects

The analysis covered sites with monthly traffic exceeding 100,000, selected from the 83rd sales ranking report released by the online shopping newspaper.

Methodology

Data was collated using Google's Chrome User Experience Report dataset. This involved comparing the Largest Contentful Paint (LCP) metrics for each domain, focusing on mobile devices and 4G connections. For further details, you can refer to Google's official documentation here.

Understanding LCP

LCP, or Largest Contentful Paint, measures the loading time for the largest visible content block on a webpage, which typically includes the most significant image or headline text. It is a critical parameter of Google's Core Web Vitals – the lower the LCP, the quicker the key content displays, leading users to perceive a faster loading experience.
Google specifies that an optimal user experience is indicated by an LCP of 2.5 seconds or less. Conversely, an LCP exceeding 4 seconds is deemed poor. Notably, based on improvement cases, such as from Renault, it is possible to achieve LCP below one second through effective optimizations.

Ranking Insights (Top 10 Performance)

Significance of Breaking the 1-Second Barrier

A noteworthy finding presents that all top 10 websites have achieved an LCP of 1.1 seconds or below, demonstrating exceptionally rapid loading times. Among the leading sites are "AmiAmi Online Shop," "Tamago Kichi," and "Shiseido Parlor," showcasing remarkable speed performance that sets an industry benchmark.

Overall Performance

Of the 275 sites examined, approximately 73.6% (201 sites) reached an LCP of 2.5 seconds or less. This reflects a growing awareness among e-commerce platforms regarding the importance of loading speed, leading to proactive improvements in performance.

Major players like Amazon have also made continuous efforts to enhance their page load speed. This is evidenced by Amazon's decreasing LCP, which improved from 1.857 seconds in February to 1.646 seconds by May, clearly indicating a commitment to performance optimization.

Major Improvements in Notable Sites

In this month’s rankings, significant optimizations were observed in sites like "Hobo Nikkan Itoi Shinbun" and "Tsutaya Books." The former reduced its LCP from 1.228 seconds to 1.068 seconds, while the latter improved from 1.275 seconds to 1.097 seconds, both surpassing the crucial 1.1-second threshold.
This progress illustrates that even sites rich in content and visual elements are investing in speed optimizations.

High-Performing Enterprises with New Core Web Vitals Indicator INP

Leading the way this month is "Tamago Kichi," which has maintained an impressive INP metric of 0.088 seconds and held the fourth position the previous month. The INP metric evaluates a webpage's responsiveness to user interactions, complementing LCP analysis for a comprehensive view of site performance. It is crucial for enterprises to consider both INP and LCP when strategizing their performance enhancements.
Improvements in scores stem from various initiatives such as:

- Optimizing JavaScript execution
- Streamlining event handlers
- Enhancing rendering performance

Thus, the continuous upgrades in both LCP and INP reflect the industry’s commitment to leveraging new technologies for site performance improvements.

For those interested in complete insights, including detailed rankings up to the 273rd position and additional case studies, please visit our media platform, MarTechLab.

Services Offered by Gaprise

Gaprise provides a range of services focused on speeding up various websites. For inquiries related to speed improvement, feel free to contact us.

About Gaprise Co., Ltd.

According to Gartner Japan, Japan's enterprise IT expenditure is forecasted to rise by 4.7% year-on-year in 2023, reaching approximately ¥28.5 trillion, with predictions to exceed ¥30 trillion by 2025. The SaaS market, currently representing about ¥1.1 trillion as of 2022 — around 4% of total expenditure — demonstrates substantial growth potential.

Since 2012, Gaprise has differentiated itself in a complex and competitive SaaS market by identifying and proposing innovative technologies from around the world. We have established substantial alliances with publicly listed firms like Monday.com and Riskified, as well as high-growth ventures such as Contentsquare and Yotpo, affirming our uniquely growing position in the market.

Furthermore, with the termination of Google's Optimize service in 2023, we are the only company in Japan to offer the three officially recommended A/B testing tools. Starting February 2024, we will also launch multiple tools aimed at website speed improvement, providing diverse solutions adaptable to our clients’ needs.

Through advanced technology implementation and consulting services, we assist businesses across a wide spectrum—conducting market analysis, enhancing online user engagement for brand awareness and acquisitions, optimizing on-site user experiences, content management, project management, and integrating AI technologies. Our commitment continues as we support business growth.

- Company Name: Gaprise Co., Ltd.
- Established: January 27, 2005
- CEO: Ryoji Kai
- Capital: ¥20 million
- Location: 2-2-1 Kanda Nishikicho, Chiyoda-ku, Tokyo, KANDA SQUARE WeWork 11F
- Corporate Site: gaprise.com