Scan report for theorem.by
5 pages crawled — 7781 words, 188 images and 762 links read straight off the pages and checked for accessibility, performance, SEO, security, forms, links and infrastructure. 45 distinct problems found, counted 164 times across the pages.
Report updated 2026-10-29
Category scores
- Overall
- 82/100
- SEO
- 90/100 · Issues: 16
- Accessibility
- 75/100 · Issues: 25
- Performance
- 79/100 · Issues: 31
- Security
- 8/100 · Issues: 39
- Privacy
- 97/100 · Issues: 1
- HTML validity
- 91/100 · Issues: 5
- Forms
- 85/100 · Issues: 15
- Links
- 97/100 · Issues: 5
- Console
- 82/100 · Issues: 10
- Infrastructure
- 97/100 · Issues: 1
- Mobile
- 86/100 · Issues: 11
- Images
- 97/100 · Issues: 5
Quick Wins
High-impact, low-effort fixes, ranked by what this scan actually found.
- Send a Strict-Transport-Security header — Browsers refuse to fall back to plain HTTP for this domain.
- Set font-display: swap on the web fonts — Text is readable in a fallback face from the first paint instead of being hidden.
- Send X-Content-Type-Options: nosniff — Browsers stop guessing content types and executing files as scripts.
- Send a Referrer-Policy header — Internal URLs stop leaking to third-party sites.
- Serve every asset over https:// — Browsers stop blocking assets and warning about the padlock.
- Label every form field — Fields become usable with a screen reader and clickable by their label.
What the site checks found
- High — Security — The TLS certificate expires in 9 days.
- Low — Security — No /.well-known/security.txt — anyone who finds a vulnerability has to guess where to report it.
- Medium — Security — No SPF record — anyone can send email that claims to come from this domain.
- Medium — Security — No DMARC record at _dmarc — nothing tells receiving servers what to do with mail that fails the SPF check.
- Low — Security — No CAA record — any certificate authority may issue a certificate for this domain.
- Low — Security — The zone is not signed with DNSSEC, so a forged DNS answer cannot be detected.
- Low — Performance — The HTML is compressed with gzip but not with Brotli, which every current browser accepts and which is typically 15–20% smaller.
- Low — Infrastructure — The domain publishes no MX records, so it cannot receive email.
- Low — Privacy — The site loads Google Analytics, Google Tag Manager, Yandex Metrica with no consent layer anywhere in the markup — under the GDPR and the ePrivacy Directive those tags need consent before they run.
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