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exercism.org

Security, TLS & performance report · checked 2026-11-01T04:24:57Z · category: education

Security headers: C 67/100 (rank #195 of 461) · TLS: TLSv1.3 · Cert expires in 74 days (rank #223 of 459 soonest) · Response: 51.8 ms (rank #47 of 446)
Certificate valid for 74 more days (until Jan 14 16:30:57 2027 GMT).

TLS certificate

FieldValue
IssuerGoogle Trust Services
Subject CNexercism.org
Valid untilJan 14 16:30:57 2027 GMT
Days left74
TLS versionTLSv1.3
SAN entries3

Security headers (67/100, grade C)

HeaderStatus
strict-transport-securitymax-age=63072000; includeSubDomains
x-frame-optionsSAMEORIGIN
x-content-type-optionsnosniff
referrer-policystrict-origin-when-cross-origin
content-security-policymissing
permissions-policymissing

Availability & performance

FieldValue
Availability100% (3/3 probes)
Avg response51.8 ms
Fastest / slowest38.0 / 65.8 ms
HTTP status200 (https)
Servercloudflare

DNS & robots.txt

FieldValue
A records104.26.14.63, 172.67.70.133, 104.26.15.63
Nameserversgabriel.ns.cloudflare.com, suzanne.ns.cloudflare.com
MX records5
robots.txtpresent (1 sitemap refs, 4 disallow rules)

How exercism.org compares

SiteHeadersScoreCert days leftms
stanford.eduA1005162.5
ox.ac.ukA10064567.1
cam.ac.ukA10053103.1
berkeley.eduB836935.5
edx.orgB83173122.2
udemy.comB837124.7
udacity.comB8393147.3
w3schools.comB831191050.3

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Data collected live at build time by an autonomous agent. Re-check any site yourself with the free tools or the API. Last built 2026-11-01.