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WISLR Performance

Core Web Vitals monitoring for the pages that earn your revenue.Lab tests and real-user data, side by side, before and after every release.

Your team ships a release on Tuesday, and by Friday checkout feels slower on a phone. WISLR Performance measures your key pages from the outside, the way Google does, on desktop and mobile, so you can see what moved and which fix comes first. Nothing goes on your site.

See WISLR Performance

  • LCP

    Largest Contentful Paint

    Good: 2.5 s or less

  • INP

    Interaction to Next Paint

    Good: 200 ms or less

  • CLS

    Cumulative Layout Shift

    Good: 0.1 or less

  • TTFB

    Time to First Byte

    Good: 0.8 s or less

Google's thresholds for a good page, measured at the 75th percentile of visits.

A green lab score can hide a red result for your real visitors

Lab tools test a page under controlled conditions. Field data records what visitors experienced in Chrome over the last 28 days, and it's the data Google uses in search. Most reports show one of the two. WISLR Performance puts both next to each other for every page you choose.

Lab: Lighthouse runs

Controlled tests on desktop and mobile, with the requests and scripts behind each number.

Field: real Chrome users

Core Web Vitals from real visits to your pages over the last 28 days.

Setup takes a list of URLs and nothing else

  1. 01

    Pick the pages that matter

    Usually five to ten of them: home, category, product, cart and checkout.

  2. 02

    We measure around every release

    A baseline first, then before and after each deployment, then monthly, so a slow drift doesn't go unnoticed.

  3. 03

    You read it in a private portal

    Reports land in your WISLR.io portal within a day, with a summary on top and the detail underneath, and we walk your team through them.

Every report ranks the fixes by what they're worth

Measure

Scores and Core Web Vitals for each key page on desktop and mobile, with the requests, scripts and layout shifts behind each number.

Compare

Before-and-after reports for any release, calling out the biggest improvements and regressions by page and device.

Improve

Findings ranked by impact, with a plain summary for the business and the technical detail your developers need to act the same day.

Share

A private portal with every report and comparison, PDF export, and access limited to the people you choose.

Built for teams whose revenue depends on a fast mobile page

Ecommerce brands

Category, product and checkout pages measured the way your customers experience them on a phone.

Teams in the middle of a replatform

A baseline before the migration and a comparison after it, so the new platform has to show it didn't slow you down.

Planning a site migration

Agencies

Run it for your clients in a white-label portal with your logo and wording, available on request.

Mobile speed moves conversion and search visibility

53%

of mobile visits are abandoned when a page takes longer than three seconds to load.

Google, 2017

8.4%

more retail conversions followed a 0.1 second improvement in mobile site speed.

Deloitte for Google, Milliseconds Make Millions, 2020

Core Web Vitals are part of the page experience signals Google Search uses to rank pages. Google Search Central

Questions teams ask before they start

What are Core Web Vitals?

Core Web Vitals are three measures Google uses to judge how a page feels to a visitor: Largest Contentful Paint for loading, Interaction to Next Paint for responsiveness, and Cumulative Layout Shift for visual stability. Google rates a page good when Largest Contentful Paint is 2.5 seconds or less, Interaction to Next Paint is 200 milliseconds or less, and Cumulative Layout Shift is 0.1 or less, measured at the 75th percentile of visits.

How is this different from running PageSpeed Insights myself?

PageSpeed Insights tests one page at one moment. WISLR Performance measures the set of pages that carry your revenue on a schedule and around every release, keeps the history, and compares each release with the one before it, with the findings ranked by impact.

Do we need to install anything?

No. Measurement happens from outside your site, the way Google measures it. There are no tags, no scripts and no access to your codebase, so monitoring can't slow your pages down.

How often are our pages measured?

A baseline first, then before and after each release you tell us about, then monthly. Reports reach your private WISLR.io portal within a day of each run.

See your numbers

Send us your site, and we'll run a baseline on your key pages and walk you through it, with no commitment.

Visit WISLR.io