Many website owners prioritize Japanese data centers when building websites, deploying programs, and setting up cross-border businesses. Japanese VPS hosting is also considered representative of "close proximity, low latency, and high stability." However, many users may encounter problems during use, such as slow access from within China, severe packet loss, and lag during peak hours, with access speeds not meeting expectations despite purchasing a Japanese VPS. So what's going on?

　　The conclusion is: Japanese VPS itself isn't slow; the slowness stems from the "network path" and "resource allocation method." Geographically, the physical distance between Japan and mainland China is very short, with theoretical latency between 30-80ms, significantly better than VPS in Europe and America. However, what truly affects the actual access experience isn't the "straight-line distance," but rather the route taken, whether it involves detours, speed limits, or being slowed down by shared resources.

　　Real-world testing revealed 7 common reasons for slow Japanese VPS speeds:

　　Reason 1: Route Selection Issues

　　The primary reason for slow Japanese VPS speeds is that the VPS uses standard international routes, not optimized routes. The access path from Japan to China might be: Japan → Hong Kong → China, resulting in unstable latency, severe packet loss during peak hours, and significant differences in experience across different ISPs.

　　Real-world testing findings: Large ping fluctuations, noticeably slower access at night, and the most prone to problems for China Telecom users.

　　Solution: Prioritize Japanese VPSs that support CN2/optimized routes to China. Don't just look at the "Japanese data center," always check the "backhaul route to China."

　　Reason 2: Bandwidth Issues

　　Many Japanese VPS providers share bandwidth, which is severely congested during peak hours. Some providers advertise 100M, 300M, or even 1G bandwidth, but these are almost always shared bandwidth. Compared to dedicated bandwidth, shared bandwidth often has some drawbacks, such as slower speeds with more users on the same node, almost guaranteed lag during peak hours, and no control over "what your neighbors are doing."

　　Real-world testing: Acceptable during the day, download speeds drop to single digits Mbps at night, with extremely slow video and image loading.

　　Solution: Choose dedicated bandwidth; avoid choosing shared bandwidth just because it's cheaper.

　　Reason 3: Hidden speed limits or QoS for cross-border traffic

　　Many service providers don't explicitly state "speed limits" on their pages, but they use technical means to implement QoS during peak hours, lowering the priority of cross-border traffic and automatically slowing down large connections.

　　Common symptoms: Small files download quickly, but multi-threaded or large files download significantly slower, with bandwidth consistently falling below the advertised value.

　　Solution: Be wary of "unlimited traffic Japan VPS"; choose packages that clearly state traffic and bandwidth limits for greater long-term stability.

　　Reason 4: Severe VPS node overselling and CPU contention

　　Slow speeds aren't always due to network issues; resource overselling is also a hidden killer. Low-priced Japanese VPS often run dozens or even hundreds of VPS instances on a single node, resulting in constant CPU contention and abnormally high IO latency.

　　Actual Test Results: Backend operations are sluggish, page load times are slow, and database response is sluggish.

　　Solution: Avoid ultra-low-priced VPS. Choose at least a 2-core, 2GB RAM configuration, prioritizing NVMe SSD nodes.

　　Reason Five: Poor IP Segment Quality, Subject to ISP Rate Limiting

　　Many Japanese VPS use abused IP segments or IPs previously used for web scraping or spam. This results in access problems in some parts of China, ISP rate throttling by some providers, and persistently high packet loss rates.

　　Solution: Choose providers offering clean IPs or IP remapping capabilities. Avoid "ultra-cheap promotional VPS."

　　Reason Six: Server Configuration Incompatible with Business Needs

　　A common and typical mistake for beginners is running WordPress on a single core and 1GB RAM, running high-concurrency programs with limited memory, neglecting caching, and relying entirely on dynamic loading. Even with a stable network, the server will be slowed down.

　　Solution: For website-related businesses, a minimum of 2 cores and 2-4GB of RAM is recommended. Enable caching (Redis/Page Cache) and use CDN for images and static resources.

　　Reason Seven: Lack of Acceleration and Architecture Optimization

　　Many people go live immediately after purchasing a Japanese VPS without any optimization, which is the "final blow" to slow speeds. Common shortcomings include not using CDN, not separating static resources, and a chaotic caching strategy.

　　Actual Test Comparison: Unoptimized loading time takes 4-6 seconds, while CDN + caching can complete it within 1-2 seconds.

　　Slow Japanese VPS is not "Japan's problem." Many website owners abandon Japanese nodes after experiencing slow speeds, which is a great pity. The real problem lies in choosing the wrong network, using the wrong plan, and not understanding optimization. As long as you avoid the 7 common pitfalls mentioned in this article, Japanese VPS remains a convenient, stable, and cost-effective overseas VPS solution.