What does StackOptic analyze?

StackOptic runs 18 analysis modules on any public website from a single URL. It detects 7,000+ technologies (CMS, frameworks, analytics, payments, CDN, hosting), evaluates SSL certificates and HTTP security headers with grades from A+ to F, measures Core Web Vitals (LCP, CLS, TBT, FCP), audits SEO meta tags and structured data, checks email security (SPF, DKIM, DMARC), analyzes AI & LLM readiness including bot access and llms.txt validation, extracts color palettes and typography, estimates carbon footprint, and generates permanent shareable reports.

Does it work on sites behind Cloudflare or bot protection?

Yes. StackOptic uses a real browser engine that loads pages exactly like a human visitor — executing JavaScript, rendering CSS, and handling redirects. This allows it to bypass Cloudflare, LiteSpeed, Sucuri, and other bot protection systems where traditional crawlers and HTTP-only tools fail.

What do I get on the free plan?

The free plan includes 5 analyses per day with access to all 18 modules, full scores, technology detection, and security grades. Every report is permanently accessible via a unique shareable URL — no login required to view. No credit card needed. AI-powered insights, re-analysis, PDF/JSON export, and comparison features are available on Pro ($24/mo) and Agency ($99/mo) plans.

What is AI & LLM readiness analysis?

This module evaluates how visible and citable your website is to AI search engines like ChatGPT, Perplexity, Google AI Overviews, and Claude. It audits access permissions for 8 major AI bots, validates llms.txt and llms-full.txt files, scores citation-ready content structure, and analyzes structured data (JSON-LD) for GEO readiness — helping you rank in the next generation of search.

How long does an analysis take?

Most analyses complete in under 10 seconds. StackOptic runs all 18 modules in parallel using a real browser session, so you get technology detection, security audit, performance metrics, SEO analysis, and AI readiness scoring simultaneously.

How accurate are the results?

Detection is based on real browser execution — DOM inspection, JavaScript runtime analysis, HTTP headers, and DNS records. With 7,000+ technology signatures and Lighthouse-calibrated performance scoring, StackOptic achieves high accuracy for mainstream technologies.

What security checks are performed?

The security module evaluates SSL/TLS certificates, 12+ HTTP security headers (HSTS, CSP, X-Frame-Options, Permissions-Policy, Referrer-Policy), HTTPS enforcement, and email authentication (SPF, DKIM, DMARC). Each site receives a letter grade from A+ to F with specific remediation steps.

Do you store the websites I analyze?

StackOptic only stores publicly available information that any visitor to a website would see — HTML content, HTTP headers, DNS records, and screenshots. We do not access private data, log in to websites, or perform any intrusive testing.

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centurylink.com

https://centurylink.com· First analyzed 20 Feb 2026· Updated 20 Feb 2026

Export

centurylink.com

Sponsored

Hosting Provider

CenturyLink Communications, LLC

IP Address

155.70.55.25

Server Location

🇺🇸 Omaha, United States

ASN

AS4015

Organization

CenturyLink Communications, LLC

CDN

Varnish

Nameservers

authns1.qwest.net.authns2.qwest.net.

Performance

Page Speed

1.7 MB

82 requests

Image Optimization

Lazy LoadResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Adobe Experience Manager

Technology Stack

6 Technologies Detected

Analytics

Libraries

CSS Frameworks

Tag Managers

Other

SEO Analysis

B70/100

centurylink.comcenturylink.com

Residential Services: Home Internet, TV, & Phone | CenturyLink

Discover CenturyLink residential home internet services. Find high-speed internet, local and long distance home phone services, TV, and special bundle offers.

Title Length62 chars

Recommended: 50-60 chars

Description Length158 chars

Recommended: 120-160 chars

Issues (0)

4 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

5 URLs

robots.txt

10 rules

Sitemap reference found

Sponsored

Security Score

76%Good

Interactive

HTTPS

No WAF

Certificate Details

Type

Organization Validated (OV)

Certificate Authority

DigiCert Inc

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/1.1

Valid From

13.02.2025

Valid Until

27.02.2026

OCSP Stapling

Enabled

Subject Alternative Names (20)

www.centurylink.comcenturylink.comcenturylink.cacenturylink.hkwww.centurylink.cawww.centurylink.hkespanol.centurylink.comespanol.shop.centurylink.com+12 more

SHA-256 Fingerprint

E9:4D:DE:AB:90:9F:CE:E6:92:C9:20:96:01:A1:39:E1:92:5F:8C:4F...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

age

112460

cache-control

🔴 No Cache(no-cache, must-revalidate, post-check=0, pre-check=0)

connection

keep-alive

content-encoding

📦 Gzip(gzip)

content-length

50929

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (2)

mxb-007e5801.gslb.pphosted.com

mxa-007e5801.gslb.pphosted.com

Domain Information

centurylink.com

Domain Age

19y 6m

Created

09.08.2006

Expires

09.08.2026

Last Updated

05.08.2025

Registrar

CSC Corporate Domains, Inc.

DNSSEC

Not Enabled

Privacy & Compliance

OneTrust

Cookie Consent Banner

OneTrust

GDPR Indicators

Cookie consent banner detected

CMP: OneTrust

Typography & Readability

MaisonNeue-book

31/100

Readability

/30

25/40

18px · LH 1.02

Hierarchy

/20

8/25

1x ratio

WCAG

/25

5/15

Contrast: undefined

Performance

/25

10/20

3 fonts

Heading Font

MaisonNeue-book

Sans18px

Body Font

MaisonNeue-book

Sans18px

Contrast Ratio

Reading Comfort

~44 CPL

Needs attention

18px

20px

18px

Minor Third

Scale

✅ Excellent readability: 18px body text is ideal for all devices.

⚠️ Tight line spacing (1.02). Consider 1.4-1.6 for better readability.

⚠️ Weak hierarchy: Headlines should be at least 2x body size for clear visual structure.

✅ Consistent design: Single font family with weight variations is a modern best practice.

✅ Smart font loading: Using font-display: swap prevents invisible text during load.

⚠️ Risky: Text appears on background images without overlay protection.

Buy on MyFonts

Business & Marketing Stack

5 Tools Detected

Enterprise

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

Quantum MetricEnterprise

User behavior and product analytics

Privacy & Cookies

OneTrustEnterprise

Cookie consent and privacy compliance tools

A/B Testing & Optimization

OptimizelyEnterprise

Experimentation and conversion optimization

Sponsored

Scripts & Styles

28 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(11)googletagmanager.com(3)cdn.quantummetric.com(1)assets.adobedtm.com(1)cdn.optimizely.com(1)

Website Identity

Facebook X (Twitter)LinkedIn YouTube

Sponsored

Last analyzed: 20 Feb 2026 at 00:07

Historical Analysis & Change Tracking