Why is my site fast for me and slow for visitors?

A warm cache. Your browser already holds the fonts, the scripts and the images, so you are measuring a repeat visit while most visitors are measuring a first one.

A fast device. Development machines are several times faster than the median phone, and main-thread work scales directly with that.

A good connection, usually wired or on strong wifi, with low latency to wherever you are.

Proximity. If the origin or the nearest edge is in your region, you are paying a fraction of the network time a distant visitor pays.

Familiarity. You know where to click, so you never wait for the thing a first-time visitor is looking for.

Disable the cache in the browser's network panel, or use a private window, so every load is a first visit.

Throttle the network and the CPU together in the performance panel. CPU throttling is the one people skip and it is usually the more revealing of the two.

Emulate a mid-range mobile device rather than a flagship, since that is closer to the median visitor.

Test while logged out. An authenticated view can be a completely different page with different scripts and different caching.

Test from another region using a service that runs from elsewhere, or simply ask a colleague in another country.

The Chrome User Experience Report aggregates real visits, which is the only source that reflects your actual audience rather than an assumed one.

It is reported at the 75th percentile, so it tells you what the slower quarter of your visitors experience.

Search Console's Core Web Vitals report groups your URLs by that assessment, which is the fastest way to find which templates are affected.

A page with too little traffic has no field data, in which case throttled laboratory testing is the substitute — with its limits stated.

Consent banners. Most first-time visitors see one and you do not, and the scripts it gates load after they answer.

Advertising and personalisation, which can differ per visitor and are frequently the heaviest part of the page.

Geography-based routing, which can serve a genuinely different origin with different performance characteristics.

Corporate networks and mobile carriers that proxy or inspect traffic, adding latency nobody on the site can see.

VeriFixScan fetches pages as an anonymous first-time visitor with no cache, which removes the largest of your five advantages automatically.

It reports `performance.page_weight`, `performance.request_count`, `performance.render_blocking` and `performance.third_party_resources` — properties of the document that do not depend on who is loading it.

`performance.ttfb` and `availability.response_time_breakdown` measure timing from where the scan runs, which is one location rather than your audience's distribution.

It cannot reproduce a specific device, a specific network or a consent state, so the stable findings are the part to act on and the timings are context.