Adv-r.hadley.nz - SEO Checker

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Overview of the SEO Check
Meta information
92% 
Page quality
67% 
Page structure
64% 
Link structure
95% 
Server
100% 
External factors
100% 
SEO Score
Response time
0.23 s
File size
12.20 kB
Words
288
Media files
2
Number of links
42 internal / 13 external

Task list of SEO Improvements

Meta specifications

Title
(Critically important)
Welcome | Advanced R
The length of the page title is perfect. (209 pixels out of 580 max pixel length)
There are no duplicate words in the title
Meta description
(Critically important)
A book created with bookdown.
The meta description is too short. (192 pixels out of 1000 max pixel length) Optimize description
Crawlability
(Critically important)
There are no problems in accessing the website.
Canonical URL
(Important)
No canonical link is specified.
Language
(Somewhat important)
Language detected in text: en
Language defined in HTML: en
Server location: United States of America
The following language is defined by HTML: en
Alternate/Hreflang Links
(Somewhat important)
There are no alternate links specified on this page.
Other meta tags
(Somewhat important)
There is no rel next meta tag on this page.
There is no rel prev meta tag on this page.
Domain
(Somewhat important)
This page is hosted on a subdomain. Use a top level domain for better SEO results.
The domain does not contain non-latin characters.
Page URL
(Somewhat important)
No parameters were found in the URL.
No session ID was found in the URL.
The URL does not have too many subdirectories.
Charset encoding
(Somewhat important)
The charset encoding (UTF-8) is set correctly.
Doctype
(Nice to have)
The doctype HTML 5 is set correctly.
The doctype is placed at first in the HTML code.
Favicon
(Nice to have)
No favicon is linked in the HTML code.

Meta tags

NameValue
viewportwidth=device-width, initial-scale=1, shrink-to-fit=no
authorHadley Wickham
generatorbookdown 0.42 with bs4_book()
descriptionA book created with bookdown.
langen
twitter:cardsummary
twitter:titleWelcome | Advanced R
twitter:descriptionA book created with bookdown.
og:titleWelcome | Advanced R
og:typebook
og:descriptionA book created with bookdown.
Content-Typetext/html; charset=UTF-8
charsetutf-8

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Page quality

Content
(Critically important)
There are only 288 words on this page. Good pages should have about 800 words of useful content.
36.1% of the text are stop words.
Keywords used in the page title are also used in the page content. That's good!
The page contains a listing, which indicates a good text layout.
5 paragraphs were found on this page.
No placeholders texts or images were found.
There are no duplicates on the site.
The average number of words per sentence of 22.29 words is good.
Frames
(Critically important)
This page does not use a frameset.
Mobile optimization
(Somewhat important)
Multiple viewport tags are given. There should only be one.
No Apple touch icon is specified.
A viewport "width=device-width, initial-scale=1, shrink-to-fit=no" is provided.
Bold and strong tags
(Somewhat important)
The usage of strong and bold tags is perfect. We recommend the use of up to 6 tags for this page.
Image SEO
(Somewhat important)
Alt text (alternative text) is correctly used on all found images.
Social Networks
(Nice to have)
There are only a few social sharing widgets on the page. Make your website popular in social networks with social sharing widgets.
Additional markup
(Nice to have)
No additional page markup was found.
HTTPS
(Somewhat important)
This website uses HTTPS to protect privacy and integrity of the exchanged data.
All included files are also transferred via HTTPS.

Media list

URLAlt attributeTitle
https://adv-r.hadley.nz/cover.pngBuy on Amazon
...tivecommons.org/l/by-nc-sa/4.0/88x31.pngCreative Commons Licence

Page structure

H1 heading
(Critically important)
Advanced R
Too many H1 headings
The H1 heading is too short (10 characters). It should be at least 20 Characters long.
Headings
(Important)
The heading structure is perfect.

Heading structure

Heading levelContent
H1 Advanced R
H1 Welcome
H2 Table of contents
H2 License
H2 Other books
H2 On this page
Some anchor texts are used more than once.
The number of internal links is ok.
None of the anchor texts is too long.
All internal links are not using dynamic parameters.
There are 13 external links on this page.

Found links on this page

LinkAttributesAnchor text
https://adv-r.hadley.nz/Anchor Skip to main content
/index.htmlAdvanced R
/index.htmlWelcome
/preface.htmlPreface
/introduction.html1 Introduction
/foundations-intro.htmlIntroduction
/names-values.html2 Names and values
/vectors-chap.html3 Vectors
/subsetting.html4 Subsetting
/control-flow.html5 Control flow
/functions.html6 Functions
/environments.html7 Environments
/conditions.html8 Conditions
https://adv-r.hadley.nz/fp.htmlText duplicate Introduction
/functionals.html9 Functionals
/function-factories.html10 Function factories
/function-operators.html11 Function operators
https://adv-r.hadley.nz/oo.htmlText duplicate Introduction
/base-types.html12 Base types
https://adv-r.hadley.nz/s3.html13 S3
https://adv-r.hadley.nz/r6.html14 R6
https://adv-r.hadley.nz/s4.html15 S4
/oo-tradeoffs.html16 Trade-offs
/metaprogramming.htmlText duplicate Introduction
/meta-big-picture.html17 Big picture
/expressions.html18 Expressions
/quasiquotation.html19 Quasiquotation
/evaluation.html20 Evaluation
/translation.html21 Translating R code
/techniques.htmlText duplicate Introduction
/debugging.html22 Debugging
/perf-measure.html23 Measuring performance
/perf-improve.html24 Improving performance
https://adv-r.hadley.nz/rcpp.html25 Rewriting R code in C++
/references.htmlReferences
https://github.com/hadley/adv-rExternal View book source
https://adv-r.hadley.nz/Anchor No Text
https://amzn.to/2WoabjBExternal IMG-ALT Buy on Amazon
https://amzn.to/2WoabjBExternal Text duplicate Advanced R
http://adv-r.had.co.nz/External Subdomain URL anchor text
http://adv-r.had.co.nz/
https://adv-r.hadley.nz/Anchor No Text
https://creativecommons.org/li...External IMG-ALT Creative Commons Licence
https://creativecommons.org/li...External Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
https://opensource.org/license...External MIT license
https://adv-r.hadley.nz/Anchor No Text
https://advanced-r-solutions.r...External Subdomain Advanced R Solutions
https://r4ds.had.co.nz/External Subdomain R for Data Science
https://r-pkgs.org/External R Packages
/preface.htmlText duplicate Preface
https://adv-r.hadley.nz/Anchor Text duplicate Welcome
https://adv-r.hadley.nz/Anchor License
https://adv-r.hadley.nz/Anchor Other books
https://github.com/hadley/adv-...External View source
https://github.com/hadley/adv-...External Edit this page
https://bookdown.org/External bookdown

Server configuration

HTTP redirects
(Critically important)
This page redirects to "https://adv-r.hadley.nz/"
HTTP header
(Important)
No X-Powered HTTP header is sent.
The web server transmits the web page (HTML) in compressed form.
Performance
(Somewhat important)
The page response time is excellent with 0.23 seconds.
The file size of the HTML document is fine (12 kB).

HTTP Response Header

NameValue
serverGitHub.com
content-typetext/html; charset=utf-8
last-modifiedThu, 13 Mar 2025 02:17:06 GMT
access-control-allow-origin*
etagW/"67d24022-30a9"
expiresTue, 18 Mar 2025 03:18:27 GMT
cache-controlmax-age=600
content-encodinggzip
x-proxy-cacheMISS
x-github-request-id6289:2A4552:2C7097D:2CC84DC:67D8E3AB
accept-rangesbytes
age0
dateWed, 19 Mar 2025 23:40:19 GMT
via1.1 varnish
x-served-bycache-fra-eddf8230033-FRA
x-cacheHIT
x-cache-hits0
x-timerS1742427619.994416,VS0,VE101
varyAccept-Encoding
x-fastly-request-id7d4a271731524c49a25cc9e6e15914750eae6243
content-length4151
statuscode200
http_versionHTTP/2

External factors

This website has excellent links from other websites.
This page has backlinks from 515 referring domains.
This page has 1,991 backlinks.
This page has backlinks from 335 different ip addresses.

Links from Wikipedia

No links from Wikipedia were found.

Robots.txt

No valid Robots.txt file was found.

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Search preview

adv-r.hadley.nz
Welcome | Advanced R
A book created with bookdown.

Most important keywords

Following keywords were found. You can check the keyword optimization of this page for each keyword.

KeywordResultRecheck
Advanced66%Check
book50%Check
Welcome50%Check
bookdown46%Check
Hadley46%Check
packages39%Check
Solutions39%Check
Data39%Check
Science39%Check
Data Science39%Check
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