Rdrr.io - SEO Checker

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Overview of the SEO Check
Meta information
100% 
Page quality
40% 
Page structure
78% 
Link structure
96% 
Server
45% 
External factors
100% 
SEO Score
Response time
0.03 s
File size
13.50 kB
Words
229
Media files
1
Number of links
27 internal / 4 external

Task list of SEO Improvements

Meta specifications

Title
(Critically important)
R Package Documentation
The length of the page title is perfect. (239 pixels out of 580 max pixel length)
There are no duplicate words in the title
Meta description
(Critically important)
A comprehensive index of R packages and documentation from CRAN, Bioconductor, GitHub and R-Forge.
The length of the meta description is perfect. (658 pixels out of 1000 max pixel length)
Crawlability
(Critically important)
There are no problems in accessing the website.
Canonical URL
(Important)
https://rdrr.io/
There is a valid canonical link specified.
Language
(Somewhat important)
Language detected in text: en
Language defined in HTML: en
Server location: Germany
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)
The domain is no subdomain.
The domain length is good.
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)
The favicon is linked correctly.

Meta tags

NameValue
viewportwidth=device-width, initial-scale=1, minimum-scale=1
descriptionA comprehensive index of R packages and documentation from CRAN, Bioconductor, GitHub and R-Forge.
langen
og:titleR Package Documentation
og:descriptionA comprehensive index of R packages and documentation from CRAN, Bioconductor, GitHub and R-Forge.
X-UA-CompatibleIE=edge
charsetutf-8

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Page quality

Content
(Critically important)
There are only 229 words on this page. Use at least 250 words to provide useful information.
Words from the H1 heading are not used in the page content.
Only 1 paragraph/s was/were found on this page.
24.5% of the text are stop words.
Keywords used in the page title are also used in the page content. That's good!
No placeholders texts or images were found.
There are no duplicates on the site.
The average number of words per sentence of 9.5 words is good.
Frames
(Critically important)
This page does not use a frameset.
Mobile optimization
(Somewhat important)
No Apple touch icon is specified.
A viewport "width=device-width, initial-scale=1, minimum-scale=1" 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)
1 images have no alt attribute. The content of alt attributes is used by search engines.
Social Networks
(Nice to have)
This page is optimized perfectly for social networks.
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
/static/images/ianhowson32.pngNo alt attribute provided

Page structure

H1 heading
(Critically important)
R Package Documentation A comprehensive index of R packages and documentation from CRAN, Bioconductor, GitHub and R-Forge.
The H1 heading is too long.
Headings
(Important)
The structure of headings is missing one or more levels. Do not skip heading levels.

Heading structure

Heading levelContent
H1 R Package Documentation A comprehensive index of R packages and documentation from CRAN, Bioconductor, GitHub and R-Forge.
H2 Search for anything R related Find an R package by name, find package documentation, find R documentation, find R functions, search R source code...
H2 Find an R package
H2 Run R code online Over 19,000 packages are preinstalled!
H2 Browse R language docs
H2 Recently updated packages
H4 R Package Documentation
H4 Browse R Packages
H4 We want your feedback!
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 4 external links on this page.

Found links on this page

LinkAttributesAnchor text
https://rdrr.io/rdrr.io
https://rdrr.io/find/Find an R package
https://rdrr.io/r/R language docs
https://rdrr.io/snippets/Run R in your browser
https://rdrr.io/all/cran/CRAN packages
https://rdrr.io/all/bioc/Bioconductor packages
https://rdrr.io/all/rforge/R-Forge packages
https://rdrr.io/all/github/GitHub packages
https://rdrr.io/find/Text duplicate Find an R package
https://rdrr.io/snippets/Run R code online Over 19,000 packages are preinstalled!
https://rdrr.io/r/Browse R language docs
https://rdrr.io/rforge/CHNOSZ/CHNOSZ Thermodynamic Calculations and Diagrams for Geochemistry
/rforge/WeightedCluster/WeightedCluster Clustering of Weighted Data
https://rdrr.io/rforge/ctv/ctv CRAN Task Views
https://rdrr.io/rforge/eRm/eRm Extended Rasch Modeling
https://rdrr.io/rforge/glarma/glarma Generalized Linear Autoregressive Moving Average Models
https://rdrr.io/rforge/semds/semds Structural Equation Multidimensional Scaling
https://rdrr.io/rforge/cfa/cfa Configural Frequency Analysis (CFA)
https://rdrr.io/rforge/homals/homals Gifi Methods for Optimal Scaling
https://twitter.com/rdrrHQExternal Tweets by rdrrHQ
https://rdrr.io/rdrr.io home
https://rdrr.io/r/R language documentation
https://rdrr.io/snippets/Run R code online
https://rdrr.io/all/cran/Text duplicate CRAN packages
https://rdrr.io/all/bioc/Text duplicate Bioconductor packages
https://rdrr.io/all/rforge/Text duplicate R-Forge packages
https://rdrr.io/all/github/Text duplicate GitHub packages
https://twitter.com/intent/twe...External Tweet to @rdrrHQ
https://github.com/rdrr-io/rdr...External GitHub issue tracker
https://ianhowson.com/External Personal blog
/snippets/embedding/Embedding Snippets

Server configuration

HTTP redirects
(Critically important)
This page redirects to "https://rdrr.io/"
HTTP header
(Important)
The HTML page should be transferred using GZip compression.
No X-Powered HTTP header is sent.
Performance
(Somewhat important)
The page response time is excellent with 0.03 seconds.
The file size of the HTML document is fine (14 kB).

HTTP Response Header

NameValue
dateTue, 27 May 2025 15:17:35 GMT
content-typetext/html; charset=utf-8
content-length13875
x-frame-optionsSAMEORIGIN
expiresTue, 27 May 2025 15:18:41 GMT
cache-controls-maxage=3600, public, max-age=3600
strict-transport-securitymax-age=15724800; includeSubDomains
statuscode200
http_versionHTTP/2

External factors

This website has excellent links from other websites.
This page has backlinks from 386 referring domains.
This page has 770 backlinks.
This page has backlinks from 333 different ip addresses.

Links from Wikipedia

No links from Wikipedia were found.

Robots.txt

User-agent: *
Disallow: 
Sitemap: https://rdrr.io/sitemap.xml
Host: rdrr.io

User-agent: Browsershots
Disallow:

Similar sites

Search preview

rdrr.io
R Package Documentation
A comprehensive index of R packages and documentation from CRAN, Bioconductor, GitHub and R-Forge.

Most important keywords

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

KeywordResultRecheck
Documentation77%Check
Package Documentation75%Check
package73%Check
packages63%Check
CRAN62%Check
GitHub62%Check
Bioconductor62%Check
R-Forge62%Check
comprehensive62%Check
index62%Check
Show more keywords and terms

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