Profile: Stackoverflow stackoverflow.com

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Stackoverflow is an online question and answer website for programmers.


  Uptime last 24 hours

  Response Time last 24 hours

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Average Rating:

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Current Status

Up

For 2 years, 8 months
(Since Jul 29, 2015 3:51 p.m. GMT)

Uptime For Period
100%
Latest Downtime
No downtime recorded.

  Web Speed Test Results

Loading timeRequestsTotal SizePerformace GradeMobile Usability
2406 ms 48 570.8 KB 67/100 99/100
Location: London, United Kingdom
Date: 2018-04-20 07:06
TypeURLSize
0.0 s
0.0 s
0.0 s
0.0 s
0.0 s
0.0 s
Script /ajax/libs/jquery/1.12.4/jquery....
ajax.googleapis.com
33.6 KB
Script /Js/stub.en.js
cdn.sstatic.net
13.5 KB
Stylesheet /Shared/stacks.css
cdn.sstatic.net
14.6 KB
Stylesheet /Sites/stackoverflow/primary.css
cdn.sstatic.net
64.8 KB
Script /ht/p/185901-159836282584097.js
js-sec.indexww.com
21.0 KB
Image /817gJ.png
i.stack.imgur.com
2.0 KB
Image /avatar/29e8b06723879cfba156b7da...
www.gravatar.com
1.0 KB
Image /Sites/stackoverflow/img/sprites...
cdn.sstatic.net
3.2 KB
Image /img/hero/pattern.svg
cdn.sstatic.net
7.1 KB
Script /clc/clc.min.js
cdn.sstatic.net
3.5 KB
Script /tag/js/gpt.js
www.googletagservices.com
6.0 KB
Script /analytics.js
www.google-analytics.com
14.4 KB
Script /quant.js
secure.quantserve.com
5.0 KB
Script /beacon.js
sb.scorecardresearch.com
1.2 KB
Image /img/favicons-sprite16.png
cdn.sstatic.net
67.9 KB
Script /Js/full-anon.en.js
cdn.sstatic.net
35.2 KB
Stylesheet /clc/styles/clc.min.css
cdn.sstatic.net
22.8 KB
Other /b
sb.scorecardresearch.com
924 B
Script /adsid/integrator.js
adservice.google.com.co
662 B
Script /adsid/integrator.js
adservice.google.com
662 B
Script /gpt/pubads_impl_196.js
securepubads.g.doubleclick.net
56.4 KB
Script /Js/snippet-javascript.en.js
cdn.sstatic.net
5.8 KB
Script /Js/post-validation.en.js
cdn.sstatic.net
3.7 KB
Script /Js/prettify-full.en.js
cdn.sstatic.net
21.7 KB
Script /Js/external-editor.en.js
cdn.sstatic.net
2.9 KB
XHR /posts/49934512/ivc/20d8
stackoverflow.com
194 B
Script /rules-p-c1rF4kxgLUzNc.js
rules.quantcount.com
338 B
Image /b2
sb.scorecardresearch.com
248 B
Other /r/collect
www.google-analytics.com
302 B
Image /Sites/stackoverflow/img/wmd-but...
cdn.sstatic.net
3.3 KB
Image /r/collect
stats.g.doubleclick.net
380 B
Image /pixel
pixel.quantserve.com
474 B
XHR /gampad/ads
securepubads.g.doubleclick.net
5.3 KB
Script /gpt/pubads_impl_rendering_196.js
securepubads.g.doubleclick.net
16.3 KB
Other /safeframe/1-0-23/html/container...
tpc.googlesyndication.com
1.8 KB
Script /pagead/js/r20180411/r20110914/c...
tpc.googlesyndication.com
1.6 KB
Script /pagead/js/r20180411/r20110914/a...
tpc.googlesyndication.com
27.2 KB
Image /simgad/16192648057432725631
tpc.googlesyndication.com
42.4 KB
Script /pagead/osd.js
pagead2.googlesyndication.com
28.7 KB
Script /ajax/libs/jquery/3.2.1/jquery.m...
ajax.googleapis.com
29.7 KB
Script /pagead/js/r20180411/r20110914/a...
tpc.googlesyndication.com
0 B
Image /pcs/view
securepubads.g.doubleclick.net
281 B
Image /pcs/view
securepubads.g.doubleclick.net
247 B
Script /markup.js
clc.stackoverflow.com
2.0 KB
Image /impression.gif
clc.stackoverflow.com
177 B
Image /pcs/activeview
pagead2.googlesyndication.com
178 B
Image /pcs/activeview
pagead2.googlesyndication.com
110 B
Other /_/client-timings
stackoverflow.com
122 B
Total requests: 48 570.8 KB Load end time: 2.4 s

Performance

Your page has 2 blocking script resources and 2 blocking CSS resources. This causes a delay in rendering your page.

None of the above-the-fold content on your page could be rendered without waiting for the following resources to load. Try to defer or asynchronously load blocking resources, or inline the critical portions of those resources directly in the HTML.

Remove render-blocking JavaScript:

  • https://cdn.sstatic.net/Js/stub.en.js?v=0cdf8dcc3f83
  • https://cdn.sstatic.net/Js/mobile.en.js?v=57f90a3e1c86

Optimize CSS Delivery of the following:

  • https://cdn.sstatic.net/Shared/stacks.css?v=669f3170a0d5
  • https://cdn.sstatic.net/Sites/stackoverflow/mobile.css?v=9d92317f3068

Your page requires additional network round trips to render the above-the-fold content. For best performance, reduce the amount of HTML needed to render above-the-fold content.

The entire HTML response was not sufficient to render the above-the-fold content. This usually indicates that additional resources, loaded after HTML parsing, were required to render above-the-fold content. Prioritize visible content that is needed for rendering above-the-fold by including it directly in the HTML response.

  • Only about 29% of the final above-the-fold content could be rendered with the full HTML response.
  • Click to see the screenshot with only the HTML response: snapshot:5

Setting an expiry date or a maximum age in the HTTP headers for static resources instructs the browser to load previously downloaded resources from local disk rather than over the network.

Leverage browser caching for the following cacheable resources:

  • https://www.gravatar.com/avatar/29e8b06723879cfba156b7da132461ff?s=30&d=identicon&r=PG (5 minutes)
  • https://www.google-analytics.com/analytics.js (2 hours)

Properly formatting and compressing images can save many bytes of data.

Optimize the following images to reduce their size by 3.6KiB (23% reduction).

  • Compressing https://cdn.sstatic.net/img/share-sprite-new.png?v=e1b8bd67bc12 could save 2.9KiB (21% reduction).
  • Compressing https://www.gravatar.com/avatar/29e8b06723879cfba156b7da132461ff?s=30&d=identicon&r=PG could save 687B (45% reduction).

Your HTML is minified. Learn more about minifying HTML.

You have compression enabled. Learn more about enabling compression.

Your server responded quickly. Learn more about server response time optimization.

Your CSS is minified. Learn more about minifying CSS.

Your page has no redirects. Learn more about avoiding landing page redirects.

Your JavaScript content is minified. Learn more about minifying JavaScript.

Mobile Usability

Some of the links/buttons on your webpage may be too small for a user to easily tap on a touchscreen. Consider making these tap targets larger to provide a better user experience.

The following tap targets are close to other nearby tap targets and may need additional spacing around them.

  • The tap target <a href="/questions/ask">Ask</a> is close to 1 other tap targets final.
  • The tap target <a class="vote-down-off">down vote</a> is close to 1 other tap targets final.
  • The tap target <a href="#" class="star-off">favorite</a> is close to 1 other tap targets final.

The text on your page is legible. Learn more about using legible font sizes.

The contents of your page fit within the viewport. Learn more about sizing content to the viewport.

Your page specifies a viewport matching the device's size, which allows it to render properly on all devices. Learn more about configuring viewports.

Your page does not appear to use plugins, which would prevent content from being usable on many platforms. Learn more about the importance of avoiding plugins.

Loading Time per Content Type

Loading Time per Domain

Size per Content Type

Size per Domain

Requests per Content Type

Requests per Domain

DateLoad speedRequestsPage size
April 20, 2018, 7:06 a.m. (current result)2.4 s48570.8 KB
April 6, 2018, 5:05 p.m.5.6 s48500.6 KB

  Domain Health Check Results

DNS
0 Errors
0 Warnings
3 Passed
Web Server
0 Errors
0 Warnings
3 Passed
Mail Server
0 Errors
0 Warnings
6 Passed
Blacklist & Malware
0 Errors
0 Warnings
2 Passed

DNS

Type Test Result
DNS Get DNS Records Click "More Info" to review your DNS records.
MX   10 alt3.aspmx.l.google.com.
MX   10 alt4.aspmx.l.google.com.
MX   1 aspmx.l.google.com.
TXT  "MS=ms52592611"
TXT  "google-site-verification=o3EMam8yBGo1yEjyybIiZcOunGHOQKpo8JmOtp9n1BU"
TXT  "google-site-verification=rdWtMbplKjbRHGr2dNONfwkqithlUvjr3u6i8QEz_mo"
TXT  "v=spf1 ip4:198.252.206.0/24 ip4:192.111.0.0/24 include:_spf.google.com include:mailgun.org ip4:64.34.80.172 include:mail.zendesk.com include:servers.mcsv.net include:sendgrid.net ~all"
WHOIS Get WHOIS Records Click "More Info" to review your WHOIS records.
Nameservers: ns-1033.awsdns-01.org,ns-358.awsdns-44.com,ns-cloud-e1.googledomains.com,ns-cloud-e2.googledomains.com
Expires: 2018-02-02
Registrar: name.com, inc.
WHOIS Domain Expiry WHOIS OK - 113 days left for domain, expires '2018-02-02'.
WHOIS OK - 113 days left for domain, expires '2018-02-02'.
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Web Server

Type Test Result
HTTP Web Server HTTP HTTP OK: HTTP/1.1 301 Moved Permanently - 674 bytes in 0.060 second response time
HTTP OK: HTTP/1.1 301 Moved Permanently - 674 bytes in 0.060 second response time
HTTPS Web Server HTTPS HTTP OK: HTTP/1.1 200 OK - 2759 bytes in 0.090 second response time
HTTP OK: HTTP/1.1 200 OK - 2759 bytes in 0.090 second response time
SSL Certificate SSL Certificate Expiry OK - Certificate '*.stackexchange.com' will expire on Wed 14 Aug 2019 12:00:00 PM UTC.
OK - Certificate '*.stackexchange.com' will expire on Wed 14 Aug 2019 12:00:00 PM UTC.
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Mail Server

Type Test Result
SMTP SMTP on aspmx.l.google.com SMTP OK - 0.062 sec. response time
SMTP OK - 0.062 sec. response time
SMTP SMTP on aspmx.l.google.com - SSL/TLS SMTP OK - 0.109 sec. response time
SMTP OK - 0.109 sec. response time
SMTP SMTP on alt4.aspmx.l.google.com SMTP OK - 0.361 sec. response time
SMTP OK - 0.361 sec. response time
SMTP SMTP on alt3.aspmx.l.google.com SMTP OK - 0.390 sec. response time
SMTP OK - 0.390 sec. response time
SMTP SMTP on alt4.aspmx.l.google.com - SSL/TLS SMTP OK - 0.693 sec. response time
SMTP OK - 0.693 sec. response time
SMTP SMTP on alt3.aspmx.l.google.com - SSL/TLS SMTP OK - 0.847 sec. response time
SMTP OK - 0.847 sec. response time
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Blacklist & Malware

Type Test Result
Virus & Malware Virus & Malware MALWARE OK
MALWARE OK
Blacklist Spam Blacklists OK: 151.101.193.69 not on known spam blacklists (91 blacklists checked.)
OK: 151.101.193.69 not on known spam blacklists
 (91 blacklists checked.)
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