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codesandbox.io

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

Security headers: F 0/100 (rank #407 of 461) · TLS: TLSv1.3 · Cert expires in 82 days (rank #252 of 459 soonest) · Response: 232.3 ms (rank #256 of 446)

Certificate valid for 82 more days (until Jan 22 16:37:46 2027 GMT).

TLS certificate

Field	Value
Issuer	Let's Encrypt
Subject CN	codesandbox.io
Valid until	Jan 22 16:37:46 2027 GMT
Days left	82
TLS version	TLSv1.3
SAN entries	2

Security headers (0/100, grade F)

Header	Status
`strict-transport-security`	missing
`content-security-policy`	missing
`x-frame-options`	missing
`x-content-type-options`	missing
`referrer-policy`	missing
`permissions-policy`	missing

Availability & performance

Field	Value
Availability	100% (3/3 probes)
Avg response	232.3 ms
Fastest / slowest	213.1 / 263.7 ms
HTTP status	200 (https)
Server	cloudflare

DNS & robots.txt

Field	Value
A records	172.64.144.247, 104.18.43.9
Nameservers	adel.ns.cloudflare.com, greg.ns.cloudflare.com
MX records	5
robots.txt	absent (n/a sitemap refs, n/a disallow rules)

How codesandbox.io compares

Site	Headers	Score	Cert days left	ms
replit.com	A	100	38	40.8
codepen.io	A	100	38	35.2
github.com	B	83	87	66.8
stackoverflow.com	B	83	71	55.0
bitbucket.org	C	67	52	231.2
jsfiddle.net	C	67	50	181.4
codeberg.org	C	50	38	486.2
sourcegraph.com	D	33	38	148.0

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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.