sudoku.com website review

A phone's processor spends 17.3 s on main-thread work while loading, 7.9 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

1 file blocks the first paint until they finish downloading. Deferring or inlining it could save about 1.6 s.

8 third-party services load with your homepage (Rubicon Project, primis.tech and Pubmatic and others), adding 3.2 MB and 4.0 s of main-thread time.

About 2.2 MB of JavaScript is downloaded but never used on this page.

109 files are served with short cache lifetimes, so returning visitors download them again (1.5 MB).

Your mobile performance score is 55 (desktop: 60). Pages that score under 90 lose visitors before the first paint.

primis.tech costs a phone 748 ms of main-thread work and 1.1 MB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

20 long tasks block the main thread while loading, the longest for 815 ms. During a long task the page ignores taps.

Rubicon Project costs a phone 770 ms of main-thread work and 79 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

Pubmatic costs a phone 702 ms of main-thread work and 67 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

Other Google APIs/SDKs costs a phone 565 ms of main-thread work and 894 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

Google/Doubleclick Ads costs a phone 348 ms of main-thread work and 436 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

Polyfills for old browsers add 82 KiB JavaScript that modern phones do not need.

8 KiB could be saved by minifying JavaScript.

Critical files load one after another instead of in parallel (3 chains). Preconnecting to key origins and preloading the hero image shortens the chain.

1 image could be 5 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

Real Chrome users on phones do not pass Google's Core Web Vitals on this page (28-day field data from the Chrome UX Report (opens in a new tab)). Google uses this in ranking.

Real visitors wait 4.1 s for the largest content to appear (75th percentile). Good is under 2.5 s.

The page becomes fully interactive after 61.7 s. Good is under 3.8 s.

Scripts block taps and scrolling for 3.5 s in total while the page loads. Good is under 200 ms.

Visually, the page fills in at 11.5 s (Speed Index). Good is under 3.4 s.

Real visitors wait 229 ms for the page to respond to a tap (75th percentile). Good is under 200 ms.

The first text or image appears after 2.1 s on a phone. Good is under 1.8 s.

Your largest element takes 2.7 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “We and our partners store and/or access information (includ…”.

Over the last 25 four-week periods to 2026-10-03, real Chrome visitors' largest content (lcp) went from 4.4 s to 4.1 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 6.6 MB in 1,337 requests on a phone: scripts 3.4 MB (57), media 1.2 MB (1) and HTML 797 KiB (261). Under 2 MB keeps phones on slow connections fast.

By the Sustainable Web Design model, a visit to your homepage emits about 1.87 g of CO₂e: 224.5 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

3 dropdowns have no label.

13 text elements don't have enough contrast against the background to read easily, especially outdoors on a phone.

3 tap targets are too small or too close together to hit reliably with a finger.

1 element hidden from screen readers can still receive keyboard focus.

The viewport tag blocks pinch-zoom, which low-vision visitors rely on.

5 form fields have no label, so screen readers announce an empty box and autofill guesses.

No structured data (JSON-LD), so Google can't show rich results such as your logo, ratings or FAQs.

No Open Graph image (also missing: og:title, og:description), so links shared on LinkedIn, Slack or Facebook show no preview picture.

No twitter:card tag. X falls back to Open Graph, which is incomplete here.

The homepage links to 137 pages on sudoku.com and 40 external pages.

There is no Organization (or LocalBusiness) JSON-LD, so search engines and AI assistants have no machine-readable facts about who runs the site: its name, logo, profiles and contact details.

https://sudoku.com/storybook and https://sudoku.com/postcards are marked noindex but linked from your homepage. If they are meant to be found, remove the noindex.

https://sudoku.com/awards has no <h1> headline, so visitors and search engines get no clear main topic.

We fetched 15 pages linked from your homepage (of 42 found) and read each the way a search engine does.

40 third-party cookies are set on load; browsers are restricting these, so whatever relies on them breaks.

1 error was logged to the browser console while the page loaded, for example “Cannot assign to read only property 'open' of object '#<Window>'”.

Chrome logged issues while loading the page (“Mixed content”).

Large scripts ship without source maps.

On a phone, there is no call to action on the first screen: visitors have to scroll to find out what to do next.

Social proof on the homepage: 5 trust badges. Pairing it with named testimonials or customer logos makes it far more convincing.

No phone number or email link on the homepage, so ready-to-buy visitors have one fewer way to reach you.

There is no form on the homepage, so every lead has to click through to another page first.

No guarantee or risk reducer (money-back, free trial, no credit card) is mentioned, which is often what tips a hesitant visitor.

The homepage carries about 698 words of visible text.

Before a visitor clicks anything, the page loads Google Ads, Google Analytics, Google Tag Manager and Meta Pixel (measured from a US location before any click). No consent tool was detected. Visitors from the EU, UK and several US states must be asked first.

Opening the homepage sets 7 cookies (measured from a US location before any click).

No known cookie consent tool loads with the page. Some sites build their own banner, and some only show one to visitors from the EU.

Loading the homepage contacts 6 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.