sios.com website review

9 files block the first paint until they finish downloading. Deferring or inlining them could save about 5.5 s.

Your mobile performance score is 65 (desktop: 91). Pages that score under 90 lose visitors before the first paint.

24 files are served with short cache lifetimes, so returning visitors download them again (587 KiB).

Google Tag Manager costs a phone 272 ms of main-thread work and 291 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 Fonts costs a phone 0 ms of main-thread work and 604 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.

3 third-party services load with your homepage (Google Tag Manager, Google Fonts and Google Analytics), adding 896 KiB and 272 ms of main-thread time.

2 long tasks block the main thread while loading, the longest for 197 ms. During a long task the page ignores taps.

About 134 KiB of JavaScript is downloaded but never used on this page.

About 30 KiB of CSS is downloaded but never applied on this page.

11 KiB could be saved by minifying CSS.

Desktop scores 91 but mobile only 65. A gap that wide usually means heavy scripts and images that hit phones hardest.

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.

3 KiB could be saved by minifying JavaScript.

The first text or image appears after 5.4 s on a phone. Good is under 1.8 s.

Your largest element takes 5.4 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “オープンソースソフトウェアとAIで、 「世界中の人々のために、不可能を可能に。」”.

Visually, the page fills in at 6.0 s (Speed Index). Good is under 3.4 s.

The page becomes fully interactive after 5.9 s. Good is under 3.8 s.

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

Over the last 25 four-week periods to 2026-10-17, real Chrome visitors' tap response (inp) went from 92 ms to 91 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-10-17, real Chrome visitors' largest content (lcp) went from 0.8 s to 0.8 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

1 image further down the page (24 KiB) download before anyone scrolls to it. Adding loading="lazy" lets the first screen load first.

By the Sustainable Web Design model, a visit to your homepage emits about 0.41 g of CO₂e: 49.8 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

1 button has no accessible name, so screen readers announce just “button”.

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

1 frame has no title, so screen-reader users cannot tell what it contains.

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

Your title is only 8 characters: “サイオス株式会社”. Between 30 and 65 characters leaves room to say what you do and for whom.

No XML sitemap at https://www.sios.com/sitemap.xml, so Google discovers your pages only by following links.

Open Graph is missing og:description, so shared links fall back to guesses.

The homepage links to 194 pages on sios.com and 8 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 https://www.sios.com/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.

https://www.sios.com/ja/company, https://www.sios.com/ja/company/message, https://www.sios.com/ja/company/dx-strategy, https://www.sios.com/ja/company/business, https://www.sios.com/ja/company/governance and https://www.sios.com/ja/company/governance/corporate-governance and 6 others have under 150 words in the HTML. Thin pages rarely rank; if the text loads with JavaScript, crawlers that don't run it see even less.

We fetched 15 pages linked from your homepage (of 94 found) and read each the way a search engine does.

3 of 10 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

1 error was logged to the browser console while the page loaded, for example “Failed to load resource: the server responded with a status of 404 ()”.

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

We found no call-to-action buttons or links (such as “Book a demo” or “Get a quote”) anywhere on the homepage.

No testimonials, customer logos, ratings or customer counts on the homepage: nothing tells a new visitor that others already trust you.

Your longest form asks for 9 fields (0 required). Every extra field lowers completion.

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

The homepage has only about 39 words of visible text; thin pages give Google and first-time buyers little to go on.

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

Before a visitor clicks anything, the page loads Google Analytics and Google Tag Manager (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 2 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 4 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.