vndoc.com

Readiness by lane

Green: vndoc.com. Thin bar: Education & Online Learning peer median.

Priority fixes for vndoc.com

Ordered by impact and by how common each practice is among peers.

1. Priority 1 · Harden

   HSTS kept for at least a year

   Observed: The homepage response did not include a Strict-Transport-Security header.

   Why it matters: HSTS tells browsers to use HTTPS for your host on every later visit, which removes the window where a first HTTP request can be intercepted.

   What to do: Send Strict-Transport-Security on HTTPS responses. Start with a short max-age (for example 300 seconds), confirm every subdomain works over HTTPS, then raise it in steps to 31536000. Add includeSubDomains only when all subdomains are HTTPS. HSTS preload is optional and hard to undo; hstspreload.org itself does not recommend it by default.

   On Cloudflare: Enable HSTS under SSL/TLS > Edge Certificates > HTTP Strict Transport Security and raise max-age gradually.

   34% of Education & Online Learning peers do this. Limit: Read from the homepage response only; other pages or regions may send different headers.

   Guide: HTTPS and TLS Guide for Website Owners

2. Priority 2 · Enable

   XML sitemap discoverable

   Observed: No sitemap was listed in robots.txt or found at /sitemap.xml.

   What to do: Generate an XML sitemap of canonical URLs, reference it in robots.txt and submit it in Google Search Console.

   65% of Education & Online Learning peers do this.

   Guide: XML Sitemap Guide: Include Only URLs You Stand Behind

3. Priority 3 · Accelerate

   Static files cached for 30 days or more

   Observed: A same-site stylesheet or script was cacheable for 14 days, short of the 30-day benchmark.

   What to do: Give versioned (fingerprinted) CSS, JavaScript, fonts and images Cache-Control: public, max-age=31536000, immutable, and change the file name whenever the content changes.

   On Cloudflare: Use Cache Rules to set edge and browser TTLs for static file paths.

   45% of Education & Online Learning peers do this.

   Guide: Browser Caching Guide for Website Owners

4. Priority 4 · Accelerate

   Modern image formats in use

   Observed: The homepage had 76 images and none used WebP or AVIF.

   What to do: Serve WebP or AVIF with a JPEG or PNG fallback, either through an image CDN or by generating both formats at build time.

   On Cloudflare: Cloudflare Polish can convert images to WebP.

   32% of Education & Online Learning peers do this.

   Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format

What vndoc.com already does well

Practices fewer than half of Education & Online Learning peers use.

• DMARC policy enforces quarantine or rejectDMARC policy p=quarantine.36% of peers
• Structured data presentJSON-LD structured data found.41% of peers
• No render-blocking scripts in <head>Head scripts load without blocking.42% of peers

What we saw

Homepage checked

https://vndoc.com/

Homepage response

HTTP 200

TLS

TLSv1.3, HTTP/2

Certificate

Sectigo, 198-day validity, expiring 2027-04-25

DNS operators

Cloudflare

DMARC policy

p=quarantine

Homepage HTML

177 KB, gzip

Images on homepage

76 (svg 58, png 15, jpg 3)

Limits: homepage only, one location, one moment. Header checks reflect the homepage response; other pages may differ.

Stack and providers

Seen in the homepage response, certificate and DNS. Provider pages compare how their customers configure the same checks.

All 31 checks

Select a gap for the method and fix. How each check works

Compare with other Education & Online Learning sites

• desmos.com57
• ducksters.com57
• unimi.it58
• unive.it58
• uv.es58

Education & Online Learning readiness benchmark