celestron.com website review

18 files are served with short cache lifetimes, so returning visitors download them again (431 KiB).

16 files block the first paint until they finish downloading. Deferring or inlining them could save about 1.9 s.

Your mobile performance score is 39. Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

A phone's processor spends 9.6 s on main-thread work while loading, 4.3 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

8 third-party services load with your homepage (mavenoid.com, Shopify and truevaultcdn.com and others), adding 1.1 MB and 2.0 s of main-thread time.

11 images could be 480 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen. Google estimates it would make the page about 150 ms faster on a phone.

mavenoid.com costs a phone 574 ms of main-thread work and 314 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.

Shopify costs a phone 525 ms of main-thread work and 350 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.

20 long tasks block the main thread while loading, the longest for 558 ms. During a long task the page ignores taps.

About 393 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 150 ms faster on a phone.

truevaultcdn.com costs a phone 440 ms of main-thread work and 95 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.

The page has 2,112 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

Web fonts hide text while they load. Setting font-display: swap shows text immediately (about 50 ms).

Polyfills for old browsers add 42 KiB JavaScript that modern phones do not need.

6 KiB JavaScript is shipped twice across bundles.

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

Scripts make the browser recalculate the layout repeatedly while the page loads, which wastes processor time on phones.

2 KiB could be saved by minifying JavaScript.

Your largest element takes 7.5 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image.

The page becomes fully interactive after 14.5 s. Good is under 3.8 s.

Scripts block taps and scrolling for 1.8 s in total while the page loads. Good is under 200 ms.

Visually, the page fills in at 6.4 s (Speed Index). Good is under 3.4 s.

The first text or image appears after 2.8 s on a phone. Good is under 1.8 s.

Over the last 25 four-week periods to 2026-10-31, real Chrome visitors' tap response (inp) went from 121 ms to 130 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 3.1 MB in 191 requests on a phone: images 1.1 MB (20), scripts 1.1 MB (95) and other files 559 KiB (33). Under 2 MB keeps phones on slow connections fast.

start-stargazing-now.jpg is on the first screen but marked loading="lazy", so the browser waits before fetching it and the page looks finished later. Load it eagerly (and give it fetchpriority="high" if it is the main image).

By the Sustainable Web Design model, a visit to your homepage emits about 0.88 g of CO₂e: 105.8 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

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

Scrollable region must have keyboard access: 1 element on the page fails this check, rated serious by axe-core.

Document should not have more than one main landmark: 1 element on the page fails this check, rated moderate by axe-core.

Landmarks should have a unique role or role/label/title (i.e. accessible name) combination: 1 element on the page fails this check, rated moderate by axe-core.

All page content should be contained by landmarks: 1 element on the page fails this check, rated moderate by axe-core.

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

Elements with visible text labels do not have matching accessible names. (1 element).

Your title is 69 characters, so Google will cut it off around 60: “Telescopes, Accessories, Outdoor and Scientific Products by Celestron”.

Your <h1> is empty.

The homepage links to 239 pages on celestron.com and 23 external pages.

/collections/all, /collections/smithsonian-by-celestron-telescopes, /collections/nexstar-se-and-nexstar-evolution, /collections/advanced-vx-computerized-telescopes, /collections/top-telescopes-under-500 and /collections/beginner-telescopes and 5 others have no meta description, so Google writes the search snippet from whatever text it finds.

/products/celestron-origin-intelligent-home-observatory has no <h1> headline, so visitors and search engines get no clear main topic.

We fetched 15 pages linked from your homepage (of 122 found) and read each the way a search engine does.

HSTS is set, but max-age is 91 days; one year is the recommended minimum.

No Referrer-Policy header, so full URLs can leak to the sites you link to.

No Permissions-Policy header to switch off camera, microphone and location for embedded content.

X-XSS-Protection is set to “1; mode=block”; the header is deprecated and can introduce bugs. Use 0 or remove it.

There is no /.well-known/security.txt telling researchers how to report a security problem to you.

celestron.com's DNS answers are not signed. DNSSEC stops attackers forging them to send visitors or email elsewhere; most registrars switch it on in a click, though most sites still run without it.

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

No analytics or tag manager detected in the HTML, so you can't measure whether any of these fixes work.

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

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 475 words of visible text.

Email authentication: SPF record 25 points, plus 15 when it ends in -all (10 for ~all); DMARC record 25, plus 25 for a reject policy (15 for quarantine); a DKIM key on a common selector 10.

Before a visitor clicks anything, the page loads Klaviyo (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 11 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 24 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.