a website’s first visitor almost always waits a little longer than its second<\/a>.<\/p>\n\n\n\nYour cache hit ratio is simply the percentage of requests that take the fast path instead of the slow one:<\/p>\n\n\n\n
Cache hit ratio = (Cache hits) \u00f7 (Cache hits + Cache misses) \u00d7 100<\/p>\n\n\n\n
If 950 out of 1,000 page views were served straight from cache, you’re sitting at a 95% cache hit ratio. The other 5% went the long way round.<\/p>\n\n\n\n
Think of it less as a performance score and more as a share of your traffic that’s actually benefiting from the caching you set up. A caching plugin that’s “on” but rarely hit is barely doing its job.<\/p>\n\n\n\n
<\/span>Why this matters more than your PageSpeed score<\/strong><\/span><\/h2>\n\n\n\nA PageSpeed Insights lab test or a GTmetrix test shows you how a specific page performed during a particular test run. A cache hit ratio answers a different question: how often requests are actually being served from cache instead of being rebuilt.<\/p>\n\n\n\n
When you can measure it across real requests, your cache hit ratio tells you what proportion of traffic is actually being served from cache. Even without an aggregate percentage, checking cache status across your most important URLs can reveal whether caching is working where it matters.<\/p>\n\n\n\n
A site can run a strong lab test and still have plenty of misses happening in production, if:<\/p>\n\n\n\n