jellyfish.co website review

8 images could be 958 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen. Google estimates it would make the page about 1.7 s faster on a phone.

11 files block the first paint until they finish downloading. Deferring or inlining them could save about 2.5 s.

About 571 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 600 ms faster on a phone.

Your mobile performance score is 59. Pages that score under 90 lose visitors before the first paint.

8 third-party services load with your homepage (Google Tag Manager, Optanon and JSDelivr CDN and others), adding 1.0 MB and 729 ms of main-thread time.

About 135 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 600 ms faster on a phone.

22 files are served with short cache lifetimes, so returning visitors download them again (305 KiB).

Google Tag Manager costs a phone 410 ms of main-thread work and 535 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.

A phone's processor spends 3.4 s on main-thread work while loading, 1.1 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

The page has 1,795 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

Polyfills for old browsers add 38 KiB JavaScript that modern phones do not need. Google estimates it would make the page about 150 ms faster on a phone.

4 long tasks block the main thread while loading, the longest for 176 ms. During a long task the page ignores taps.

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.

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.

Your largest element takes 12.2 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image “Jellyfish data hub”.

The page becomes fully interactive after 16.2 s. Good is under 3.8 s.

The first text or image appears after 3.2 s on a phone. Good is under 1.8 s.

Real visitors see the first content after 1.9 s (75th percentile). Good is under 1.8 s.

42 images have no width and height attributes, so the layout jumps as each one loads.

Visually, the page fills in at 4.6 s (Speed Index). Good is under 3.4 s.

The layout shifts by 0.144 while loading, so content jumps under the reader's thumb. Good is under 0.1.

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' tap response (inp) went from 123 ms to 143 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' largest content (lcp) went from 2.2 s to 2.6 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 4.1 MB in 171 requests on a phone: images 2.5 MB (82), scripts 1.3 MB (44) and fonts 162 KiB (7). Under 2 MB keeps phones on slow connections fast.

9 images are downloaded at several times the size a phone draws them, for example Uli-Abend.png at 612 px wide, shown at 48 px. Resized copies would save about 1.1 MB.

11 images further down the page (1.2 MB) download before anyone scrolls to them. Adding loading="lazy" lets the first screen load first.

3 images (592 KiB) are JPEG, PNG or GIF. The same pictures as WebP or AVIF are usually much smaller at the same quality, and every current browser shows them.

By the Sustainable Web Design model, a visit to your homepage emits about 1.17 g of CO₂e: 140.6 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

25 images have no alt text, which hurts accessibility and image search.

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

6 visible links have no text or label, so screen readers cannot say where they go.

Elements with role="dialog" or role="alertdialog" do not have accessible names. (1 element).

Headings skip levels (h2 → h4 and h2 → h4), which makes the page harder to scan with a screen reader.

1 link use generic text like “click here” or “learn more”, which tells Google nothing about the page behind it.

The homepage links to 165 pages on jellyfish.co and 13 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.

There is no /llms.txt, a short Markdown guide to your key pages for AI tools (llmstxt.org). It is optional and few AI tools read it yet, so treat it as a cheap extra.

/solutions/engineering-product-operations/team-workflow-analysis and /solutions/engineering-product-operations/people-management have no meta description, so Google writes the search snippet from whatever text it finds.

We fetched 15 pages linked from your homepage (of 70 found) and read each the way a search engine does.

2 errors were logged to the browser console while the page loaded, for example “Uncaught TypeError: Failed to execute 'observe' on 'MutationObserver': parameter 1 is not of type 'Node'.”.

1 link to other sites is dead, for example https://academy.jellyfish.co/app (404).

No Content-Security-Policy header, the main browser-side defence against injected scripts.

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.

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 967 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 Google Ads, Google Analytics, Google Tag Manager, LinkedIn Insight and Reddit Pixel (measured from a US location before any click). A consent tool (OneTrust) is installed; check it blocks these until visitors agree where the law requires it.

Opening the homepage sets 15 cookies, 1 of them by other companies (measured from a US location before any click).

Loading the homepage contacts 40 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.