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zulip.org

https://zulip.org· First analyzed 14 May 2026· Updated 14 May 2026
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zulip.org
Desktop screenshot of zulip.org
Mobile screenshot of zulip.org
Mobile

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Hosting Provider

Amazon Web Services (AWS)
aws.amazon.com

IP Address

54.145.154.103

Site Location

🇺🇸 United Statesvia ip

Server Location

🇺🇸 Ashburn, United States

ASN

AS14618

Organization

AWS EC2 (us-east-1)

Server

Nginx

Nameservers

ns-453.awsdns-56.com.ns-751.awsdns-29.net.ns-1263.awsdns-29.org.ns-1914.awsdns-47.co.uk.

Performance

88

Core Web Vitals

Weight

First Contentful Paint
1.6 s10%
Speed Index
2.1 s10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
584 KB
23 requests

Image Optimization

Lazy LoadWebPResponsive
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
Infrastructure
Hosting
Amazon Web Services (AWS)

Technology Stack

3 Technologies Detected

CSS Frameworks

1
Tailwind CSS

Web Servers

1
Nginxv1.24.0

Analytics

1
Sentry

SEO Analysis

C65/100
19
5
1
Meta Tags7/15
Content12/12
Headings8/8
Technical14/21
E-E-A-T0/7
Images3/7
Links5/5
URL5/5
Social4/5
Freshness0/4
Mobile4/4
Indexability3/3
Z
zulip.orgzulip.org

Zulip — organized team chat

Zulip is an organized team chat app for distributed teams of all sizes.

Title Length27 chars

Recommended: 50-60 chars (~163px / 580px)

Description Length73 chars

Recommended: 120-160 chars

Issues (1)

  • • Most images missing alt text (9/9) — critical for accessibility and SEO

6 issues found

Upgrade to view details

Local SEO

Local Search Readiness

6/100
Poor
2 13 2

This site doesn't appear to be a local business. Local SEO signals are optional for non-local websites.

Sponsored

AI & LLM Readiness

D43/100
Bot Access
20/25
Machine Read.
10/25
Schema Data
0/25
Citation
13/25

AI Bot Access

14/14 accessible
AI Search
OAI-SearchBot
PerplexityBot
Claude-SearchBot
Gemini-Deep-Research
DuckAssistBot
Training
GPTBot
ClaudeBot
Google-Extended
Meta-ExternalAgent
Bytespiderinfo
Amazonbot
Applebot-Extended
CCBotinfo
Fetch
ChatGPT-User

Machine Readability

llms.txt
llms-full.txt
Semantic HTML
Heading Hierarchy
nav
Text ratio:13%
Words:895
Token eff.:Optimal
Sections/1K:10.1
Depth:1/5

Structured Data

No Schema

Citation Readiness

Opening Summary311w
Descriptive Headingsavg 2.7w
Canonical URL
Open Graph3/3
Twitter Card1/3
Language Tag
Publish Date
Author Info
Lists
Tables
TL;DR / Summary
About Page Link
Recommendations (11)
AI readiness recommendation preview...
Upgrade to view recommendations

Sponsored

Accessibility

WCAG 2.1 Compliance

Evaluates how accessible your website is for users with disabilities, based on WCAG 2.1 guidelines. Checks images, forms, keyboard navigation, ARIA roles, and color contrast.
B
72/100
9
Passed
4
Critical
0
Warnings
Images & Alt Text
20/20
Checks if images have descriptive alt text for screen readers and visually impaired users.
Semantic Structure
15/20
Evaluates proper use of HTML5 semantic elements (header, nav, main, footer) and heading hierarchy.
Forms & Inputs
15/15
Verifies form fields have labels, error messages are clear, and inputs are properly associated.
Color & Contrast
15/15
Tests text-to-background color contrast ratios against WCAG AA/AAA minimum requirements.
Keyboard & Focus
6/15
Ensures all interactive elements are reachable and operable via keyboard (tab, enter, escape).
ARIA & Roles
1/15
Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.
1 recommendation
  • •Accessibility recommendation preview...
Upgrade to view recommendations

Carbon Footprint

SWDM v4 · Eco-Score

Carbon emissions estimated using the Sustainable Web Design Model v4 (SWDM v4). Factors in data center, network, and device energy across new and returning visitors. Grade thresholds based on HTTP Archive percentiles.
73/100
A
59 mg
CO₂e / view
583.7 KB
Page Weight
80%
Cleaner Than
New Visitor
67 mg
vs
Returning (cached)
34 mg
Annual (10K/mo)
7.1 kg
Emission Segments
Data Center
3 mg
Network
17 mg
Device
39 mg
Resource Breakdown
Images
506.7 KB
CSS
68.6 KB
HTML
8.3 KB
Green Hosting Verified
Amazon Web Services (AWS)
Provider Match
4 recommendations
  • •Carbon footprint recommendation preview...
Upgrade to view recommendations
A+

Security Score

93%Excellent
Static / Informational

HTTPS

No WAF

295d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Amazon

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-256

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

04.02.2026

Valid Until

05.03.2027

OCSP Stapling

Enabled

Subject Alternative Names (2)

zulip.com*.zulip.com

SHA-256 Fingerprint

C7:E1:AA:FE:DA:FD:FC:46:23:C5:12:E5:2B:0B:49:0F:EA:9B:29:AD...

Recommendations

Security recommendation preview

Upgrade to view recommendations
Upgrade to view header details

HTTP Headers

Developer Console

content-encoding
📦 Gzip(gzip)
content-language
en-gb
content-type
text/html; charset=utf-8
cross-origin-opener-policy
same-origin
date
Thu, 14 May 2026 15:47:42 GMT
referrer-policy
strict-origin-when-cross-origin
Good Warning Issue

Email Infrastructure

Google Workspace

Score

75

SPF
DKIM
DMARC

DMARC Policy

Reject (Strictest)

MX Records (5)

aspmx3.googlemail.com
aspmx.l.google.com
alt1.aspmx.l.google.com
alt2.aspmx.l.google.com

+1 more

Domain Information

zulip.org

Domain Age
12y 10m

Created

02.07.2013

Expires

02.07.2026

Last Updated

07.06.2025

Registrar

NameCheap, Inc.

DNSSEC
Not Enabled

Privacy & Compliance

Cookie Consent Banner
Privacy Policy
Terms of Service

GDPR Indicators

Privacy policy page linked

Mobile Compatibility

Viewport & Responsive Test

Tests how well your website works on mobile devices. Checks viewport configuration, responsive layout, touch targets, font readability, and simulates rendering across different screen sizes.
D
58/100
Mobile Friendly1 breakpoint
Viewport Meta
The viewport meta tag tells mobile browsers how to scale the page. Without it, mobile devices render at desktop width.
Responsive Design
Uses CSS media queries or flexible layouts to adapt content to different screen sizes automatically.
Touch Icons
Apple touch icons and favicons displayed when users add the site to their home screen on mobile devices.
Readable Font Size
Base font size should be at least 16px on mobile to ensure text is readable without zooming.
Relative Units
Using em, rem, %, or vw instead of fixed px values allows content to scale properly across screen sizes.
No H-Scroll Risk
No elements wider than the viewport that would cause horizontal scrolling on mobile devices.
Tap Targets OK
Interactive elements (buttons, links) are at least 48x48px with enough spacing to prevent accidental taps.
No Fixed Widths
No elements with fixed pixel widths that could overflow on smaller screens and break the layout.
Viewport
width=device-width, initial-scale=1.0
2 recommendations
  • •Mobile compatibility recommendation preview...
Upgrade to view recommendations

Typography & Readability

Source Sans 3 VF + Open Sans Variable

WCAG AAA
83/100
Readability
/30
27/30

21px · LH 1.40

Hierarchy
/20
17/20

2.76x ratio · ✓ H1→H6

WCAG
/25
23/25

20.04:1 min contrast

Performance
/25
16/25

2 fonts

Heading Font

Source Sans 3 VF

Sans58px

Body Font

Open Sans Variable

Sans21px

Contrast Ratio

20.04:1

WCAG AAA (≥7:1)

Reading Comfort

Dual Sans-Serif

left aligned
58px
h1
50px
h2
18px
h3
30px
h4
21px
p

✅ Excellent readability: 21px body text is ideal for all devices.

✅ Optimal line spacing: 1.40 ratio (ideal range 1.4–1.6).

⚠️ Hard to read: Flesch score 40/100. Simplify sentences for wider reach.

✅ WCAG AAA contrast: All text meets 7:1 ratio (min 20.0:1).

✅ Perfect heading hierarchy: Sequential h1→h2→h3 with single H1 — ideal for SEO & accessibility.

✅ Strong hierarchy: Headlines are 2.8x larger than body text.

Buy on MyFontsFlesch 41

Color Palette

7 unique colors
Light
#ffffff
Text· 30.799999999999997%
#7da7d0
Primary· 21.7%
#5f92c3
Secondary· 10.5%
#3e5381
Secondary· 7.5%
#b4bdc5
Secondary· 5.8%
#396cb7
Accent· 3.6%

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

1
Google AnalyticsFree

User behavior and product analytics

1

Categories

1

Total Tools

0

Enterprise

0

Mid-Market

Assessment: Growing marketing technology adoption

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Scripts & Styles

12 Resources

9
Scripts
3
Styles
0
Async
9
Defer

Top Script Sources

static.zulipchat.com(9)

Website Identity

zulip.org

12 years old
Location detected: 🇺🇸 United Statesvia ip
NameCheap, Inc.📧 Google Workspaceen-gb

Social Profiles

LinkedInGitHubBluesky

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Last analyzed: 14 May 2026 at 15:47

Historical Analysis & Change Tracking