cocalc.com

.com crawl

First seen 2026-04-11 · Last seen 2026-05-18 · ok HTTP/1.1 200 1155 ms crawled 2026-05-18

US · 104.26.6.215 · AS13335 Cloudflare, Inc.

Reputation 100/100

Classifying

HTML metadata

Title

Collaborative Calculation and Data Science

Description

CoCalc landing pages and documentation

Language

Feeds

Technology

CDN: Cloudflare
CMS: Next.js

Social

Registration

Registrar

GoDaddy.com, LLC

Created

2016-07-28

Expires

2026-07-28 70 days left

Updated

2025-07-28

Name servers

candy.ns.cloudflare.com
rajeev.ns.cloudflare.com

DNS records live

NS

candy.ns.cloudflare.com
rajeev.ns.cloudflare.com

MX

1 aspmx.l.google.com
10 aspmx2.googlemail.com
10 aspmx3.googlemail.com
5 alt1.aspmx.l.google.com
5 alt2.aspmx.l.google.com

TXT

Probely=a1b31ff4-b415-453a-b4b9-c47508401bb4
google-site-verification=HbMcCvKagjTjySFvp1Du5Y0yPiwND-Rd_r4VRuRhaHw
google-site-verification=Vj0ojJyVjqMMH6uRha9i9IsKJega2kOvhdvm_Tz9an4

Email authentication strong

SPF

v=spf1 include:sagemath.com -all

strict (-all)

DMARC

v=DMARC1;p=reject;sp=reject;pct=100;rua=mailto:da5c7b65ff@rua.easydmarc.eu;ruf=mailto:da5c7b65ff@ruf.easydmarc.eu;aspf=r;adkim=r;fo=0

policy: reject (enforced) · sp=reject

DKIM

google: v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA3OnyUpPCS1dtFEGlnVJGhAC/AUNFOaywont+sSFzgF4iU/CY2FHfaspJJ6cDBm3jp+4G4Bvg4V5Ybx…
s1: k=rsa; t=s; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwmmy/x5TpQKExempxmraGcWvGbBCfr3vyFpKAseGZtWN6yxs5A03CUBPMQGMdrpjP/NPyz4wOI23qv3TWm…
s2: k=rsa; t=s; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDU8oGTTPAnQxxFUfigufGfyWM1EpN+xuEpxGX2whG4dNRXrexA/10az/KbsRoDKMQsqDu3g1ezagimo1a70fTYWd…

selectors probed

Certificate (current)

WE1

from 2026-05-08 to 2026-08-06

Expires in 79 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 85/100 Checked live page: https://cocalc.com/

present

strict-transport-security
content-security-policy
x-content-type-options
referrer-policy
permissions-policy

findings

CSP uses wildcard sources
missing frame protection

Header values

referrer-policy: strict-origin-when-cross-origin
permissions-policy: camera=*; microphone=*; fullscreen=(self "https://www.youtube-nocookie.com" "https://www.youtube.com" "https://player.vimeo.com"); picture-in-picture=(self "https://www.youtube-nocookie.com" "https://www.youtube.com" "https://player.vimeo.com")
x-content-type-options: nosniff
content-security-policy: frame-ancestors 'self' https://*.minervaproject.com https://*.kgi.edu https://dev.harald.schil.ly https://*.doulos.com https://*.codesignal.com https://roamresearch.com;
strict-transport-security: max-age=31536000; includeSubdomains; preload