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fastify.dev

https://fastify.dev· First analyzed 09 May 2026· Updated 09 May 2026
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fastify.dev
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Mobile screenshot of fastify.dev
Mobile

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Hosting Provider

GitHub Pages
pages.github.com

IP Address

185.199.108.153

Site Location

🇺🇸 United Statesvia ip

Server Location

🇺🇸 San Francisco, United States

ASN

AS54113

Organization

GitHub, Inc

Server

GitHub.com

CDN

Fastly

Nameservers

kianchau.ns.cloudflare.com.vera.ns.cloudflare.com.

Performance

100

Core Web Vitals

Weight

First Contentful Paint
639 ms10%
Speed Index
831 ms10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
2.6 MB
63 requests

Image Optimization

Lazy Load
0–49
50–89
90–100

Architecture Stack

JAMstack
⚡ SSG
Frontend
Framework
Docusaurusv3.10.1
Infrastructure
Platform
GitHub Pages
CDN
Fastly

Technology Stack

2 Technologies Detected

CSS Frameworks

1
Tailwind CSS

Fonts

1
Google Fonts

SEO Analysis

B71/100
21
6
0
Meta Tags11/15
Content10/12
Headings6/8
Technical17/25
E-E-A-T0/7
Images5/7
Links5/5
URL5/5
Social5/5
Freshness0/4
Mobile4/4
Indexability3/3
F
fastify.devfastify.dev

Fast and low overhead web framework, for Node.js | Fastify

Fast and low overhead web framework, for Node.js

Title Length58 chars

Recommended: 50-60 chars (~359px / 580px)

Description Length48 chars

Recommended: 120-160 chars

Issues (0)

    6 issues found

    Upgrade to view details

    Crawlability

    Sitemap

    Type: standard

    547 URLs

    robots.txt

    Local SEO

    Local Search Readiness

    8/100
    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

    D51/100
    Bot Access
    20/25
    Machine Read.
    18/25
    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.txtinvalid
    llms-full.txt
    Semantic HTML
    Heading Hierarchy
    code blocksnav
    Text ratio:4%
    Words:1,570
    Token eff.:Optimal
    Sections/1K:3.2
    Depth:2/5

    Structured Data

    No Schema

    Citation Readiness

    Opening Summary67w
    Descriptive Headingsavg 2.8w
    Canonical URL
    Open Graph3/3
    Twitter Card3/3
    Language Tag
    Publish Date
    Author Info
    Lists
    Tables
    TL;DR / Summary
    About Page Link
    Recommendations (9)
    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.
    A
    84/100
    13
    Passed
    2
    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
    13/15
    Ensures all interactive elements are reachable and operable via keyboard (tab, enter, escape).
    ARIA & Roles
    6/15
    Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.

    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.
    38/100
    E
    330 mg
    CO₂e / view
    2.6 MB
    Page Weight
    30%
    Cleaner Than
    New Visitor
    377 mg
    vs
    Returning (cached)
    189 mg
    Annual (10K/mo)
    39.6 kg
    Emission Segments
    Data Center
    74 mg
    Network
    79 mg
    Device
    177 mg
    Resource Breakdown
    JavaScript
    2.4 MB
    Images
    168.8 KB
    CSS
    18.7 KB
    HTML
    14.9 KB
    Green Hosting Not Verified
    GitHub Pages
    3 recommendations
    • •Carbon footprint recommendation preview...
    Upgrade to view recommendations
    B

    Security Score

    76%Good
    Static / Informational

    HTTPS

    No WAF

    82d

    Certificate Details

    Type

    Domain Validated (DV)

    Certificate Authority

    Let's Encrypt

    Key Algorithm

    RSA (2048 bit)

    Signature

    SHA-256 with RSA

    TLS Version

    TLSv1.3

    HTTP Protocol

    HTTP/2

    Valid From

    02.05.2026

    Valid Until

    31.07.2026

    Subject Alternative Names (2)

    fastify.devwww.fastify.dev

    SHA-256 Fingerprint

    22:16:98:B0:2D:03:5D:42:B2:3A:0E:2A:B3:42:F9:03:FC:6E:B8:6F...

    Recommendations

    Security recommendation preview

    Upgrade to view recommendations
    Upgrade to view header details

    HTTP Headers

    Developer Console

    accept-ranges
    bytes
    access-control-allow-origin
    *
    age
    502
    cache-control
    🟡 600s(max-age=600)
    content-encoding
    📦 Gzip(gzip)
    content-length
    14933
    Good Warning Issue

    Email Infrastructure

    Custom Mail Server

    Score

    45

    SPF
    DKIM
    DMARC

    MX Records (3)

    route3.mx.cloudflare.net
    route2.mx.cloudflare.net
    route1.mx.cloudflare.net

    Domain Information

    fastify.dev

    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.
    C
    66/100
    Mobile Friendly
    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
    1 recommendation
    • •Mobile compatibility recommendation preview...
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    Typography & Readability

    -apple-system

    WCAG Partial
    73/100
    Readability
    /30
    24/30

    16px · LH 1.65

    Hierarchy
    /20
    17/20

    2x ratio

    WCAG
    /25
    13/25

    1.17:1 min contrast

    Performance
    /25
    19/25

    System fonts

    Heading Font

    -apple-system

    Sans32px

    Body Font

    -apple-system

    Sans16px

    Contrast Ratio

    1.17:1

    7 issues

    Reading Comfort

    ~38 CPL

    Narrow lines
    32px
    h1
    24px
    h2
    20px
    h3
    16px
    p

    ✅ Excellent readability: 16px body text is ideal for all devices.

    ⚠️ Hard to read: Flesch score 38/100. Simplify sentences for wider reach.

    ⚠️ Partial contrast: 7 elements below WCAG AA threshold (min 1.2:1).

    ⚠️ Minor heading issue: 0 level skip(s) detected. Maintain sequential order for screen readers.

    ✅ Strong hierarchy: Headlines are 2.0x larger than body text.

    ⚠️ Fluid type without rem: clamp() detected but missing rem units. May fail WCAG 1.4.4 zoom test.

    Fluid TypeFlesch 38

    Color Palette

    6 unique colors
    16.29:1 AAA Light
    #ffffff
    Background· 53.8%
    #202020
    Text· 35.1%

    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

    Sponsored

    Scripts & Styles

    3 Resources

    2
    Scripts
    1
    Styles
    0
    Async
    2
    Defer

    Top Script Sources

    local(2)

    Website Identity

    fastify.dev

    Location detected: 🇺🇸 United Statesvia ip
    en

    Sponsored

    Last analyzed: 09 May 2026 at 06:23

    Historical Analysis & Change Tracking