Infrastructure - https://hackmd.io BeaverCheck Audit

D

CDN & Delivery

Action

No CDN detected

FIX

No CDN detected

A CDN can significantly improve load times for users around the world by caching content at edge nodes closer to them.

No CDN detected

Consider using a CDN to improve global delivery speed and reduce origin load.

B

HTTP Probe Timing

Total 972 ms — DNS, TCP, TLS, TTFB, content transfer breakdown

REVIEW

DNS Lookup

29 ms

TCP Connect

1 ms

TLS Handshake

660 ms

Time to First Byte

965 ms

Total Time

973 ms

Connection waterfall

DNS Lookup 29 ms TCP Connect 1 ms TLS Handshake 660 ms Server Processing 276 ms Content Transfer 8 ms

B

TLS Certificate Expiry & Recommendations

286 days until leaf cert expires — 4 issues to address

REVIEW

Certificate validity

286

days left

0d 30d 60d 90d+

Recommended actions

Prefer TLS 1.3 — TLS 1.2 is acceptable but TLS 1.3 removes RSA key exchange and improves latency
Submit your domain to hstspreload.org to be added to the Chrome preload list
Enable DNSSEC on your domain for DNS spoofing protection
Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy

A+

DNS Records

2 A records, 29 ms lookup

PASS

2 A records, 29 ms lookup

Resolves to 2 IPv4 address(es)

Got: 99.83.179.177, 75.2.77.152

Has 3 IPv6 (AAAA) record(s)

Got: 2406:da14:88d:a102:2226:ba9a:7be5:cedc, 2406:da14:88d:a101:c8d3:407a:7783:9dba, 2406:da14:88d:a100:de55:c641:f047:affa

4 nameserver(s) configured

Got: ns-845.awsdns-41.net, ns-1925.awsdns-48.co.uk, ns-1444.awsdns-52.org, ns-221.awsdns-27.com

5 mail exchanger(s) configured

CAA records not checked

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

SPF record present in TXT

DNS resolution time: 29 ms

Got: 29 ms

A	99.83.179.177, 75.2.77.152
AAAA	2406:da14:88d:a102:2226:ba9a:7be5:cedc, 2406:da14:88d:a101:c8d3:407a:7783:9dba, 2406:da14:88d:a100:de55:c641:f047:affa
CNAME	—
NS	ns-845.awsdns-41.net, ns-1925.awsdns-48.co.uk, ns-1444.awsdns-52.org, ns-221.awsdns-27.com
MX	1 aspmx.l.google.com 5 alt2.aspmx.l.google.com 5 alt1.aspmx.l.google.com 10 alt4.aspmx.l.google.com 10 alt3.aspmx.l.google.com
TXT	1password-site-verification=57QCQRGM55BBXPSVY7HZ2PLKJ4 SPF v=spf1 include:amazonses.com include:zoho.com include:servers.mcsv.net include:m... google-site-verification=4C6HQbZYXANAOkpGxSjVMQ5Y2rnkxnDKI5foWeuv5tU google-site-verification=Yr_Bo_yeVoZeSEPkuJe4pugd0xb7gNecEcm0VauL3Xc apple-domain-verification=HnlQ3AxJK6XOBK37 MS=ms17207355 linkedin-site-verification=5d31432e-bc68-4ef3-9cee-139129f957b4 google-site-verification=d-uL-RwYIwGp2juReXK632sSBTtVCCKWghWmt2fC05s cursor-domain-verification-2jk9c4=aMLb6LeKrCxC5zZDxaO6YViu0 bw=8qGCJqfuH16sCug6AQzGtfUnzPCoeYlw2CtDDqrVUlQE
CAA	Lookup not available with standard resolver

Resolved in 29 ms

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

Why this matters

Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.

A+

Redirect Chain

No redirects — direct access

PASS

No redirects — direct access

Got: https://hackmd.io

https://hackmd.io

934 ms · HTTP/1.1 FINAL

#	URL	Status	Time	Protocol	Server
1	https://hackmd.io	200	934 ms	HTTP/1.1

A+

IPv6 Readiness

IPv6 reachable (224 ms)

PASS

IPv6 reachable (224 ms)

IPv6 is configured and reachable at 2406:da14:88d:a102:2226:ba9a:7be5:cedc, 2406:da14:88d:a101:c8d3:407a:7783:9dba, 2406:da14:88d:a100:de55:c641:f047:affa

Got: 224 ms connect

IPv6 Ready

AAAA Records 2406:da14:88d:a102:2226:ba9a:7be5:cedc, 2406:da14:88d:a101:c8d3:407a:7783:9dba, 2406:da14:88d:a100:de55:c641:f047:affa Connection Reachable (224 ms)

A+

Crawlability

robots.txt present, sitemap with 13 URLs

PASS

robots.txt present, sitemap with 13 URLs

robots.txt is present

Got: 10240 bytes

sitemap.xml is present

sitemap.xml is valid XML

sitemap.xml contains 13 entries

Sitemap index with 13 child sitemaps

robots.txt does not reference a sitemap

Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Why this matters

robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.

Source: sitemaps.org

robots.txt 200 OK

Size 10240 B Sitemaps referenced 0 User-agents Blocking No — crawling allowed

<!DOCTYPE html><html class="scroll-smooth" lang="robots.txt"><head><meta charSet="utf-8"/><meta name="viewport" content="width=device-width, initial-scale=1"/><link rel="preload" as="image" href="/logos/Arweave logomark.png"/><link rel="preload" as="image" href="/logos/Avalanche_Horizontal_White.png"/><link rel="preload" as="image" href="/logos/Base_Wordmark_White.png"/><link rel="preload" as="image" href="/logos/Blockfuse_L2.png"/><link rel="preload" as="image" href="/logos/Bokeh Logo Inverted.png"/><link rel="preload" as="image" href="/logos/Brown.png"/><link rel="preload" as="image" href="/logos/ContinuousFoundation_logo.png"/><link rel="preload" as="image" href="/logos/DevOpsDays.png"/><link rel="preload" as="image" href="/logos/ETH.png"/><link rel="preload" as="image" href="/logos/brightid.svg"/><link rel="stylesheet" href="/_next/static/chunks/a4d44b71c308de05.css" data-precedence="next"/><link rel="stylesheet" href="/_next/static/chunks/ab94802ba5ab4af4.css" data-precedence="next"/><link rel="stylesheet" href="/_next/static/chunks/786710bc80ba0dc8.css" data-precedence="next"/><link rel="preload" as="script" fetchPriority="low" href="/_next/static/chunks/d5c79332a1584318.js"/><script src="/_next/static/chunks/352249a356f41352.js" async=""></script><script src="/_next/static/chunks/bf9c1cba9711df19.js" async=""></script><script src="/_next/static/chunks/90dc6678905ee329.js" async=""></script><script src="/_next/static/chunks/turbopack-33cea5077725590e.js" async=""></script><script src="/_next/static/chunks/5f61266cc010ad33.js" async=""></script><script src="/_next/static/chunks/b53512c697a241ee.js" async=""></script><script src="/_next/static/chunks/79164d74d07c8aa2.js" async=""></script><script src="/_next/static/chunks/be1d781b53904caa.js" async=""></script><script src="/_next/static/chunks/c16b3dec3847a615.js" async=""></script><script src="/_next/static/chunks/41d714fa11a5f3a3.js" async=""></script><script src="/_next/static/chunks/77aa8de66231a6fb.js" async=""></script><link rel="preload" as="image" href="/logos/openjs-foundation-logo-horizontal-white.svg"/><link rel="preload" as="image" href="/logos/g0v.png"/><link rel="preload" as="image" href="/logos/GenerativeAI_logo.png"/><link rel="preload" as="image" href="/logos/Lido.png"/><link rel="preload" as="image" href="/logos/Rust_logo.png"/><link rel="preload" as="image" href="/logos/Scipy-logo.png"/><link rel="preload" as="image" href="/logos/Sitcon.png"/><link rel="preload" as="image" href="/logos/Slice Wordmark.png"/><link rel="preload" as="image" href="/logos/SN-Linear-Flat colour.png"/><link rel="preload" as="image" href="/logos/TheMeeFoundation_logo.png"/><link rel="preload" as="image" href="/logos/Updraft.png"/><meta name="next-size-adjust" content=""/><link rel="icon" href="/favicon.svg"/><title>HackMD: Your Collaborative Markdown Workspace for Knowledge Sharing</title><meta name="description" content="HackMD gives you a real-time Markdown editor for collaborative work. Working with Markdown files in HackMD is simple, straightforward, and fun."/><link rel="canonical" href="https://hackmd.io/robots.txt"/><meta property="og:title" content="HackMD: Your Collaborative Markdown Workspace for Knowledge Sharing"/><meta property="og:description" content="HackMD gives you a real-time Markdown editor for collaborative work. Working with Markdown files in HackMD is simple, straightforward, and fun."/><meta property="og:image" content="https://hackmd.io/cover.png"/><meta name="twitter:card" content="summary_large_image"/><meta name="twitter:title" content="HackMD: Your Collaborative Markdown Workspace for Knowledge Sharing"/><meta name="twitter:description" content="HackMD gives you a real-time Markdown editor for collaborative work. Working with Markdown files in HackMD is simple, straightforward, and fun."/><meta name="twitter:image" content="https://hackmd.io/cover.png"/><script type="application/ld+json">{"@context":"https://schema.org","@type":"Organization","url":"https://hackmd.io","name":"HackMD","description":"A collaborative Markdown editor for you and your team to create, share, and edit documents in real-time. Sign up for free today.","publishingPrinciples":"https://hackmd.io/s/terms","logo":{"@type":"ImageObject","url":"https://hackmd.io/hackmd-icon-1024.png"},"sameAs":["https://www.facebook.com/hackmdio","https://twitter.com/hackmdio","https://www.linkedin.com/company/hackmd/","https://www.producthunt.com/products/hackmd","https://www.g2.com/products/hackmd"]}</script><script src="/_next/static/chunks/a6dad97d9634a72d.js" noModule=""></script></head><body class="inter_1b545fac-module__b8QJrq__variable readex_pro_8e0ef3f9-module__FZgEYG__variable roboto_mono_6c47b916-module__wl38kG__variable montserrat_5dda6b3b-module__rCOIyW__variable zen_dots_a42a89e0-module__pyg46a__variable cc--darkmode"><div hidden=""><!--$--><!--/$--></div><main class="flex min-h-screen flex-col bg-zinc-900 text-white"><nav class="flex w-full flex-row items-center justify-between px-4 py-3 text-white md:px-6 before:absolute before:left-0 before:top-0 before:z-[-1] before:h-[var(--blur-before-height)] before:w-full before:bg-[#18181B80] before:backdrop-blur-[12px] before:transition-[max-height,background-color] before:duration-200 fixed top-0 z-50" style="--blur-before-height:100%"><a class="flex" href="/home?utm_source=home&amp;utm_medium=nav-bar"><span class="inline-flex h-[20px] gap-1 md:h-[30px]"><img alt="HackMD Logo" loading="lazy" width="0" height="0" decoding="async" data-nimg="1" class="inline h-full w-auto" style="color:transparent" src="/logo-full.svg"/></span></a><section class="flex flex-col gap-7 absolute left-0 top-[100%] h-auto max-h-0 w-full overflow-hidden md:static md:max-h-fit md:w-fit transition-[max-height] duration-200 bg-inherit z-10"><form class="flex flex-col gap-6 overflow-hidden px-[30px] pb-[26px] pt-7 md:flex-row md:gap-7 md:p-0" method="post"><input type="hidden" class="hidden" name="_csrf" value="9X0SslM2-8ekGiPv7CJyIqfcZNHBOL1mRf2A"/><a href="/solutions?utm_source=home&amp;utm_medium=nav-bar"><span class="flex flex-row gap-1.5 items-center relative font-inter text-white underline decoration-transparent hocus:decoration-white transition-colors duration-100 ease-in-out justify-start md:justify-center">Solutions</span></a><a href="/pricing?utm_source=home&amp;utm_medium=nav-bar"><span class="flex flex-row gap-1.5 items-center relative font-inter text-white underline decoration-transparent hocus:decoration-white transition-colors duration-100 ease-in-out justify-start md:justify-center">Pricing</span></a><a href="/enterprise?utm_source=home&amp;utm_medium=nav-bar"><span class="flex flex-row gap-1.5 items-center relative font-inter text-white underline decoration-transparent hocus:decoration-white transition-colors duration-100 ease-in-out justify-start md:justify-center">Enterprise</span></a><a href="/developers?utm_source=home&amp;utm_medium=nav-bar"><span class="flex flex-row gap-1.5 items-center relative font-inter text-white underline decoration-transparent hocus:decoration-white transition-colors duration-100 ease-in-out justify-start md:justify-center">Developers</span></a><a href="/about?utm_source=home&amp;utm_medium=nav-bar"><span class="flex flex-row gap-1.5 items-center relative font-inter text-white underline decoration-transparent hocus:decoration-white transition-colors duration-100 ease-in-out justify-start md:justify-center">About</span></a><a href="https://hackmd.io/c/tutorials?utm_source=home&amp;utm_medium=nav-bar"><span class="flex flex-row gap-1.5 items-center relative font-inter text-white underline decoration-transparent hocus:decoration-white transition-colors duration-100 ease-in-out justify-start md:justify-center">Learn</span></a><a href="/blog?utm_source=home&amp;utm_medium=nav-bar"><span class="flex flex-row gap-1.5 items-center relative font-inter text-white underline decoration-transparent hocus:decoration-white transition-colors duration-100 ease-in-out justify-start md:justify-center">Blog</span></a><a class="flex-row gap-1.5 justify-center items-center relative font-inter rounded px-2.5 py-2 text-normal font-normal leading-normal flex bg-transparent text-text-default border border-solid border-border-default hocus:bg-element-bg-hover hocus:border-element-border-hover hocus:text-text-emphasize focus:shadow-[0_0_0_2px_#77777733] disabled:bg-element-bg-disabled disabled:border-element-border-disabled disabled:text-element-text-disabled disabled:hocus:bg-element-bg-disabled disabled:hocus:border-element-border-disabled disabled:hocus:text-element-text-disabled disabled:border disabled:border-solid disabled:hocus:border disabled:hocus:border-solid mt-1 md:hidden plausible-event-name=HomeHeaderSignin" href="https://hackmd.io/login">Sign in</a></form></section><form class="flex flex-row items-center justify-center gap-2.5 md:gap-2" method="post"><input type="hidden" class="hidden" name="_csrf" value="9X0SslM2-8ekGiPv7CJyIqfcZNHBOL1mRf2A"/><a class="flex-row gap-1.5 justify-center items-center relative font-inter rounded px-2.5 text-normal font-normal leading-normal bg-transparent text-text-default border border-solid border-border-default hocus:bg-element-bg-hover hocus:border-element-border-hover hocus:text-text-emphasize focus:shadow-[0_0_0_2px_#77777733] disabled:bg-element-bg-disabled disabled:border-element-border-disabled disabled:text-element-text-disabled disabled:hocus:bg-element-bg-disabled disabled:hocus:border-element-border-disabled disabled:hocus:text-element-text-disabled disabled:border disabled:border-solid disabled:hocus:border disabled:hocus:border-solid hidden h-fit py-1.5 md:flex plausible-event-name=HomeHeaderSignin" href="https://hackmd.io/login">Sign in</a><a class="flex flex-row gap-1.5 justify-center items-center relative font-inter text-white text-body leading-body py-[7px] px-4 rounded group plausible-event-name=HomeSignupHeader" href="https://hackmd.io/join?signup-event=HomeSignupCompleted" type="button"><div class="pointer-events-none absolute h-full w-full overflow-hidden opacity-100 group-hover:opacity-0 group-focus:opacity-0" style="border-radius:4px"><svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%"

sitemap.xml 200 OK

Type Sitemap Index URLs 13 entries Valid XML Yes

Child Sitemaps:

A+

URL Variants

www/non-www, trailing slash, HTTP→HTTPS

PASS

www/non-www, trailing slash, HTTP→HTTPS

www/non-www redirect configured correctly (preferred: non-www)

HTTP correctly 301-redirects to HTTPS

www / non-www

301https://www.hackmd.io/

200https://hackmd.io/

Preferred variant: non-www

HTTP → HTTPS

301http://hackmd.io/ → https://hackmd.io:443/

Consistent

A+

Domain Intelligence

hackmd.io — via Gandi SAS, 11 years, 1 months old

PASS

hackmd.io — via Gandi SAS, 11 years, 1 months old

Domain registered until Apr 20, 2027 (1 years remaining)

Registrar: Gandi SAS

Registrar lock is enabled

Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.

Domain expiry

276 days

April 20, 2027

SSL certificate

286 days

Issued by Amazon

Domain age

11 years, 1 months

Registered April 20, 2015

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2406:da14:88d:a101:c8d3:407a:7783:9dba

Registrar

Gandi SAS

Locked 4 NS records

Expiry timeline

Today

+1 year

Domain expiry SSL expiry Danger zone (≤30 days)

Registrar Gandi SAS

Created April 20, 2015 (11 years, 1 months ago)

Expires April 20, 2027 (1 years)

Last Updated March 21, 2026

Name Servers ns-1925.awsdns-48.co.uk, ns-221.awsdns-27.com, ns-845.awsdns-41.net, ns-1444.awsdns-52.org

Registrant HackMD

Hosting

IP Address 2406:da14:88d:a101:c8d3:407a:7783:9dba

Data source: whois (1.1s)

Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.

Why this matters

Registrar lock (clientTransferProhibited et al.) prevents unauthorized domain transfers — strongest defense against domain hijacking.

Source: ICANN / domain-security best practice