Reactivex.io - SEO Checker

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Overview of the SEO Check
Meta information
58% 
Page quality
66% 
Page structure
70% 
Link structure
90% 
Server
100% 
External factors
100% 
SEO Score
Response time
0.31 s
File size
17.00 kB
Words
293
Media files
6
Number of links
22 internal / 27 external

Task list of SEO Improvements

Meta specifications

Title
(Critically important)
ReactiveX
The page title is too short. (91 pixels of 580 max pixel length) Optimize title
The page title is only one word.
There are no duplicate words in the title
Meta description
(Critically important)
The meta description is missing.
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-us
Server location: United States of America
The following language is defined by HTML: en-us
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)
No favicon is linked in the HTML code.

Meta tags

NameValue
viewportwidth=device-width, initial-scale=1
langen-us
X-UA-CompatibleIE=edge,chrome=1
charsetutf-8

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Page quality

Content
(Critically important)
There are only 293 words on this page. Good pages should have about 800 words of useful content.
30.4% of the text are stop words.
The page contains a listing, which indicates a good text layout.
4 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 20.25 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" 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)
2 images have no alt attribute. The content of alt attributes is used by search engines.
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://reactivex.io/assets/Rx_Icon.pngNo alt attribute provided
https://reactivex.io/assets/Rx_Logo_S.pngReactiveX
https://reactivex.io/assets/wand.svgCreate
https://reactivex.io/assets/join.svgCombine
https://reactivex.io/assets/ear.svgListen
/assets/Rx_Logo_BW_S.pngNo alt attribute provided

Page structure

H1 heading
(Critically important)
ReactiveX ReactiveX
Too many H1 headings
The H1 heading is too short (19 characters). It should be at least 20 Characters long.
Headings
(Important)
The heading structure is perfect.

Heading structure

Heading levelContent
H1 ReactiveX ReactiveX
H1 The Observer pattern done right
H1 Ubiquitous
H1 Better codebases
H1 Reactive Revolution
H1 We use ReactiveX
H2 An API for asynchronous programming with observable streams
H2 CREATE Create
H2 COMBINE Combine
H2 LISTEN Listen
H2 FRONTEND
H2 CROSS-PLATFORM
H2 BACKEND
H3 Functional
H3 Less is more
H3 Async error handling
H3 Concurrency made easy
H3 ReactiveX is more than an API, it's an idea and a breakthrough in programming. It has inspired several other APIs, frameworks, and even programming languages.
H4 ReactiveX is a combination of the best ideas from the Observer pattern, the Iterator pattern, and functional programming
H4 ReactiveX is everywhere, and it's meant for everything.
H4 Documentation
H4 Languages
H4 Resources
H4 Community
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 too many external links (27) on this page.

Found links on this page

LinkAttributesAnchor text
https://reactivex.io/ReactiveX
https://reactivex.io/intro.htmlIntroduction
/documentation/observable.htmlObservable
/documentation/operators.htmlOperators
/documentation/single.htmlSingle
/documentation/subject.htmlSubject
/documentation/scheduler.htmlScheduler
https://github.com/ReactiveX/R...External RxJava
https://github.com/ReactiveX/rxjsExternal RxJS
https://github.com/Reactive-Ex...External Rx.NET
https://reactivex.io/rxscalaRxScala
https://github.com/ReactiveX/R...External RxClojure
https://github.com/ReactiveX/R...External RxSwift
/languages.htmlOthers
/tutorials.htmlTutorials
https://github.com/ReactiveXExternal GitHub
https://twitter.com/ReactiveXExternal Twitter
/community.htmlText duplicate Others
/languages.htmlChoose your platform
http://www.applied-duality.com/External Subdomain No Text
http://rx.codeplex.com/External Subdomain No Text
http://netflix.github.io/External Subdomain No Text
http://github.com/External No Text
http://soundcloud.com/External No Text
https://www.trello.com/External Subdomain No Text
http://teamtreehouse.com/External No Text
https://seatgeek.com/External No Text
http://www.oovoo.com/External Subdomain No Text
http://www.couchbase.com/External Subdomain No Text
http://www.futurice.com/External Subdomain No Text
http://www.octanner.com/External Subdomain No Text
https://www.airbnb.com/External Subdomain No Text
/documentation/observable.htmlText duplicate Observable
/documentation/operators.htmlText duplicate Operators
/documentation/single.htmlText duplicate Single
/documentation/subject.htmlText duplicate Subject
/documentation/scheduler.htmlText duplicate Scheduler
https://github.com/ReactiveX/R...External Text duplicate RxJava
https://github.com/ReactiveX/rxjsExternal Text duplicate RxJS
https://github.com/Reactive-Ex...External Text duplicate Rx.NET
https://reactivex.io/rxscalaText duplicate RxScala
https://github.com/ReactiveX/R...External Text duplicate RxClojure
https://github.com/ReactiveX/R...External Text duplicate RxSwift
/languages.htmlText duplicate Others
/tutorials.htmlText duplicate Tutorials
https://github.com/ReactiveXExternal Text duplicate GitHub
https://twitter.com/ReactiveXExternal Text duplicate Twitter
/community.htmlText duplicate Others
https://reactivex.io/Anchor No Text

Server configuration

HTTP redirects
(Critically important)
This page redirects to "https://reactivex.io/"
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 0.31 seconds.
The file size of the HTML document is fine (17 kB).

HTTP Response Header

NameValue
serverGitHub.com
content-typetext/html; charset=utf-8
last-modifiedMon, 10 Jun 2024 07:12:11 GMT
access-control-allow-origin*
etagW/"6666a74b-440b"
expiresSat, 19 Jul 2025 01:41:58 GMT
cache-controlmax-age=600
content-encodinggzip
x-proxy-cacheMISS
x-github-request-id2B33:1FC8E8:5E7C85:5FFBC7:687AF58B
accept-rangesbytes
dateSat, 19 Jul 2025 14:11:24 GMT
via1.1 varnish
age15
x-served-bycache-fra-eddf8230129-FRA
x-cacheHIT
x-cache-hits1
x-timerS1752934284.057207,VS0,VE5
varyAccept-Encoding
x-fastly-request-id67fc9e6ab2b650e84e4ba8a371714c70f8a4ffe3
content-length3883
statuscode200
http_versionHTTP/2

External factors

This website has excellent links from other websites.
This page has backlinks from 425 referring domains.
This page has 817 backlinks.
This page has backlinks from 340 different ip addresses.

Links from Wikipedia

No links from Wikipedia were found.

Robots.txt

No valid Robots.txt file was found.

Similar sites

Search preview

reactivex.io
ReactiveX

Most important keywords

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

KeywordResultRecheck
ReactiveX77%Check
programming43%Check
API43%Check
pattern43%Check
Languages43%Check
Observer43%Check
functional43%Check
functional programming43%Check
Async43%Check
idea43%Check
Show more keywords and terms

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