teltarif.de

Readiness by lane

Green: teltarif.de. Thin bar: Telecommunications & Internet peer median.

Priority fixes for teltarif.de

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.

   54% of Telecommunications & Internet 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 · Accelerate

   Modern image formats in use

   Observed: The homepage had 94 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.

   52% of Telecommunications & Internet peers do this.

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

3. Priority 3 · Harden

   Framing restricted

   Observed: The homepage did not send frame-ancestors or X-Frame-Options, so other sites may frame it.

   What to do: Send Content-Security-Policy: frame-ancestors 'self' (or a list of trusted origins). X-Frame-Options: SAMEORIGIN covers older browsers.

   68% of Telecommunications & Internet peers do this.

   Guide: A Practical Website Health Check for Owners

4. Priority 4 · Harden

   Content Security Policy present

   Observed: The homepage response did not include a Content-Security-Policy header.

   What to do: Start with Content-Security-Policy-Report-Only to see what would break, tighten the policy over a few weeks, then enforce it.

   48% of Telecommunications & Internet peers do this.

   Guide: Payment Security and PCI DSS: What Website Owners Need to Know

What teltarif.de already does well

Practices fewer than half of Telecommunications & Internet peers use.

• Certificate lifetime of 100 days or lessShort-lived 89-day certificate from Let's Encrypt, already inside the 2027 limit.28% of peers
• Reachable over IPv6IPv6 address published.33% of peers
• No render-blocking scripts in <head>Head scripts load without blocking.37% of peers

What we saw

Homepage checked

https://www.teltarif.de/

Homepage response

HTTP 200

TLS

TLSv1.3, HTTP/2

Certificate

Let's Encrypt, 89-day validity, expiring 2026-11-23

DNS operators

1 self-run or other nameserver domain

DMARC policy

p=quarantine

Homepage HTML

137 KB, gzip

Images on homepage

94 (jpg 132, png 7, svg 1)

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 Telecommunications & Internet sites

• mci.ir71
• orange.be71
• telenor.se71
• tp-link.com71
• uqwimax.jp71

Telecommunications & Internet readiness benchmark