desmos.com website review

1 file is served with short cache lifetimes, so returning visitors download them again (1.1 MB).

About 619 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 3.0 s faster on a phone.

2 files block the first paint until they finish downloading. Deferring or inlining them could save about 1.4 s.

Your mobile performance score is 50 (desktop: 67). Pages that score under 90 lose visitors before the first paint.

5 long tasks block the main thread while loading, the longest for 734 ms. During a long task the page ignores taps.

A phone's processor spends 3.1 s on main-thread work while loading, 1.6 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

About 112 KiB of CSS is downloaded but never applied on this page.

Web fonts hide text while they load. Setting font-display: swap shows text immediately (about 100 ms).

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.

1 image could be 4 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

1 third-party service load with your homepage (Bugsnag), adding 1 KiB and 0 ms of main-thread time.

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 9.4 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “At Desmos Studio, we want to help everyone learn math, love…”.

The page becomes fully interactive after 9.6 s. Good is under 3.8 s.

Scripts block taps and scrolling for 833 ms in total while the page loads. Good is under 200 ms.

Real visitors wait 823 ms for your server to start answering (75th percentile). Good is under 800 ms.

Visually, the page fills in at 5.5 s (Speed Index). Good is under 3.4 s.

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

Over the last 25 four-week periods to 2026-10-03, real Chrome visitors' tap response (inp) went from 200 ms to 196 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-10-03, real Chrome visitors' largest content (lcp) went from 2.0 s to 2.0 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

By the Sustainable Web Design model, a visit to your homepage emits about 0.44 g of CO₂e: 52.6 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

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

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

There is no <h1>, so neither visitors nor Google get a clear main headline.

Your title is only 29 characters: “Desmos | Beautiful free math.”. Between 30 and 65 characters leaves room to say what you do and for whom.

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

Your meta description is 170 characters; Google truncates after about 160, so the end of your pitch is cut.

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

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

The homepage links to only 0 pages on your own site, so visitors and crawlers find few routes into the rest of it.

No favicon is declared in the HTML, so browser tabs and Google's mobile results may show a generic icon.

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

A phone browser shows 343 words, but the HTML your server sends has only 1. GPTBot, ClaudeBot and PerplexityBot read that HTML without running JavaScript, so they see an almost empty page. Server-side rendering or pre-rendering fixes it.

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.

8 of 27 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

Large scripts ship without source maps.

No Strict-Transport-Security header, so browsers may still try plain http first on a return visit.

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

Neither X-Frame-Options nor a CSP frame-ancestors policy is set, so any site can embed yours in a frame.

X-Content-Type-Options: nosniff is missing, so browsers may guess file types.

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.

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

desmos.com has no CAA record, so any certificate authority may issue a certificate for it. A CAA record naming your provider (for example letsencrypt.org) closes that door.

desmos.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.

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.

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.

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 343 words of visible text.

DMARC is set to p=none, so mail pretending to be desmos.com is still delivered. Reports are on, so moving to quarantine is the next step.

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.

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 1 host run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.