check-host.cc Check-host.cc

   
Check server and websites for performance - worldwide free

Domain Summary

What is the traffic rank for Check-host.cc?

• Check-host.cc ranks #3,546,834 globally on HypeStat.

What percent of global Internet users visit Check-host.cc?

• 1.48E-5% of global Internet users visit Check-host.cc

How many people visit Check-host.cc each day?

• Check-host.cc receives approximately 727 visitors and 1,161 page impressions per day.

Which countries does Check-host.cc receive most of its visitors from?

• Check-host.cc is mostly visited by people located in Russian Federation,Belarus,United States.

How much Check-host.cc can earn?

• Check-host.cc should earn about $3.71/day from advertising revenue.

What is Check-host.cc estimated value?

• Estimated value of Check-host.cc is $3,516.84.

What IP addresses does Check-host.cc resolve to?

• Check-host.cc resolves to the IP addresses 2606:4700:3032::ac43:90e3, 172.67.144.227.

Where are Check-host.cc servers located in?

• Check-host.cc has servers located in United States.

check-host.cc Profile

Title:Check server and websites for performance - worldwide free
Description:Free lookup tool to check informations about IP Address or Website. Including geolocation, ISP, rDNS and more. Ping, HTTP check, TCP, UDP port and DNS.
Tags:
free check
free api
check website
whois
dns resolver
dns check
free monitoring
ip location
whois checker
check ip
website monitoring
subnet calculator
ip geolocation
udp port
availability checker
whois check
tcp port
Category:Computers Electronics and Technology / Computer Security
Edit Site Info

What technologies does check-host.cc use?

These are the technologies used at check-host.cc. check-host.cc has a total of 7 technologies installed in 6 different categories.
UI frameworks
Bootstrap Bootstrap
CDN
CloudFlare CloudFlare
Security
HSTS HSTS
Miscellaneous
HTTP/3 HTTP/3
Popper Popper
JavaScript Libraries
jQuery jQuery
Maps
Leaflet Leaflet

check-host.cc Traffic Analysis

Check-host.cc is ranked #3,546,834 in the world. This website is viewed by an estimated 727 visitors daily, generating a total of 1.2K pageviews. This equates to about 22K monthly visitors. Check-host.cc traffic has decreased by 50.02% compared to last month.
Daily Visitors727
43.64%
Monthly Visits22K
50.02%
Pages per Visit1.60
44.07%
Visit duration04:38
37.59%
Bounce Rate41.29%
128.95%
Is this your site?Verify your site's metrics.
Daily Unique Visitors:
727
Monthly Visits:
22,028
Pages per Visit:
1.60
Daily Pageviews:
1,161
Avg. visit duration:
04:38
Bounce rate:
41.29%
Global Reach:
1.48E-5%
Monthly Visits (SEMrush):
4,899
Monthly Unique Visitors (SEMrush):
2,917
Monthly Visits (SimilarWeb):
22,261
HypeRank:
3,546,834
SEMrush Rank:
2,258,407
SimilarWeb Rank:
989,584
*All traffic values are estimates only.

Traffic sources

Direct:
77.24%
Referral:
19.70%
Search:
3.06%
Social:
0%
Paid:
0%

Desktop vs Mobile

Desktop:
100.00%
Mobile:
0%

Total Visits Last 3 Months

23.8K
OCT
44.1K
NOV
22K
DEC

Visitors by country

Country
Users%
 
Russian Federation 7.15%
 
Belarus 7.02%
 
United States 6.76%
 
Spain 6.21%
 
Viet Nam 5.45%

Which sites are competitors to check-host.cc?

Websites similar to check-host.cc are sites similar on user interests and browsing behavior. Users can discover new websites that are similar to the ones they already enjoy or find useful.
Last update was 389 days ago
     
This can take up to 60 seconds. Please wait...

*HypeStat.com is not promoting or affiliated with check-host.cc in any way. Only publicly available statistics data are displayed.

Search Engine Indexes ▼

Search engine indexes are huge databases or collections of net pages that search engines like google like google and yahoo use to retrieve applicable facts while customers carry out searches. These indexes are created through search engines like google and yahoo through crawling and indexing net pages from throughout the internet.
Bing Index:
2,490

  ▼

SEMrush is a complete on line advertising and marketing platform that gives a extensive variety of gear and functions to help companies and entrepreneurs in enhancing their on line visibility and optimizing their virtual advertising and marketing strategies.
SemRushSemRush
Domain:
  check-host.cc
Rank:
(Rank based on keywords, cost and organic traffic)
  2,258,407
Organic Keywords:
(Number of keywords in top 20 Google SERP)
  30
Organic Traffic:
(Number of visitors coming from top 20 search results)
  212
Organic Cost:
((How much need to spend if get same number of visitors from Google Adwords)
  $899.00
Full SEMrush Report >>

Revenue report ▼

Google.com would generate approximately $3.7 per day if the source of income were advertisements, which equates to an estimated monthly revenue of $111.3 and annual gross revenue of approximately $1.4K. Based on these figures, the site's net worth is estimated at around $3.5K.

How much would check-host.cc make?

Daily Revenue:
$3.71
Monthly Revenue:
$111.30
Yearly Revenue:
$1,354.15
*All earnings values are estimates only.

Daily earning by country

 
CountryPageviewsEarning
 
United States 78$0.38
 
Belarus 82$0.04
 
Spain 72$0.03
 
Russian Federation 83$0.03
 
Viet Nam 63$0.03

Loss of money due to Adblock?

Daily Revenue Loss:
$0.08
Monthly Revenue Loss:
$2.47
Yearly Revenue Loss:
$30.09
Daily Pageviews Blocked:
43
Monthly Pageviews Blocked:
1,305
Yearly Pageviews Blocked:
15,872

Daily revenue loss by country

 
CountryBlockedLost Money
 
United States 14$0.07
 
Spain 14$0.01
 
Belarus 8$0.00
 
Russian Federation 5$0.00
 
Viet Nam 3$0.00

How much is check-host.cc worth?

Website Value:
$3.5K

Ad Experience Report ▼

Summary of the ad experience rating of a website for a specific platform.

Mobile summary

Root domain:
check-host.cc
Ad filtering:
(Chrome is not filtering ads on your site.)
Off
Status:
(The status of the site that is reviewed for the Better Ads Standards.)
Not reviewed

Desktop summary

Root domain:
check-host.cc
Ad filtering:
(Chrome is not filtering ads on your site.)
Off
Status:
(The status of the site that is reviewed for the Better Ads Standards.)
Not reviewed

Abusive Experience Report ▼

Summary of the abusive experience rating of a website.
Root domain:
check-host.cc
Enforcement:
(Chrome is not preventing your site from opening new windows or tabs.)
Off
Status:
(The status of the site reviewed for the abusive experiences.)
Not reviewed

Where is check-host.cc hosted? ▼

Check-host.cc may be hosted in multiple data centers distributed in different locations around the world. This is probably just one of them.

How fast does check-host.cc load? ▼

The average loading time of check-host.cc is 173 ms. The Desktop speed index is 98 and mobile speed index is 80.
Average Load Time:
173 ms

Page Speed (Google PageSpeed Insights) - Desktop

98
0-49 50-89 90-100 i

Field Data

Over the last 30 days, the field data shows that this page has a FAST speed compared to other pages in the Chrome User Experience Report.We are showing the 90th percentile of FCP and the 95th percentile of FID.

Cumulative Layout Shift (CLS)2ms 94% of loads for this page have a fast (<0.01s) Cumulative Layout Shift (CLS) 94% 3% of loads for this page have an average (0.01s ~ 0.025s) Cumulative Layout Shift (CLS) 3% 1% of loads for this page have a slow (>0.025s) Cumulative Layout Shift (CLS) 1%
Time To First Byte (TTFB)394ms 92% of loads for this page have a fast (<0.8s) Time To First Byte (TTFB) 92% 6% of loads for this page have an average (0.8s ~ 1.8s) Time To First Byte (TTFB) 6% 1% of loads for this page have a slow (>1.8s) Time To First Byte (TTFB) 1%
First Contentful Paint (FCP)973ms 92% of loads for this page have a fast (<1.8s) First Contentful Paint (FCP) 92% 5% of loads for this page have an average (1.8s ~ 3s) First Contentful Paint (FCP) 5% 2% of loads for this page have a slow (>3s) First Contentful Paint (FCP) 2%
First Input Delay (FID)1ms 99% of loads for this page have a fast (<100ms) First Input Delay (FID) 99% 0% of loads for this page have an average (100ms ~ 300ms) First Input Delay (FID) 0% 0% of loads for this page have a slow (>300ms) First Input Delay (FID) 0%
Interaction To Next Paint (INP)50ms 95% of loads for this page have a fast (<200ms) Interaction To Next Paint (INP) 95% 2% of loads for this page have an average (200ms ~ 500ms) Interaction To Next Paint (INP) 2% 1% of loads for this page have a slow (>500ms) Interaction To Next Paint (INP) 1%
Largest Contentful Paint (LCP)1.3s 92% of loads for this page have a fast (<2500ms) Largest Contentful Paint (LCP) 92% 4% of loads for this page have an average (2500ms ~ 4000ms) Largest Contentful Paint (LCP) 4% 2% of loads for this page have a slow (>4000ms) Largest Contentful Paint (LCP) 2%

Origin Data

All pages served from this origin have an FAST speed compared to other pages in the Chrome User Experience Report. over the last 30 days.To view suggestions tailored to each page, analyze individual page URLs.

Cumulative Layout Shift (CLS)3ms 92% of loads for this page have a fast (<0.01s) Cumulative Layout Shift (CLS) 92% 4% of loads for this page have an average (0.01s ~ 0.025s) Cumulative Layout Shift (CLS) 4% 2% of loads for this page have a slow (>0.025s) Cumulative Layout Shift (CLS) 2%
Time To First Byte (TTFB)433ms 91% of loads for this page have a fast (<0.8s) Time To First Byte (TTFB) 91% 7% of loads for this page have an average (0.8s ~ 1.8s) Time To First Byte (TTFB) 7% 1% of loads for this page have a slow (>1.8s) Time To First Byte (TTFB) 1%
First Contentful Paint (FCP)1.0s 91% of loads for this page have a fast (<1.8s) First Contentful Paint (FCP) 91% 5% of loads for this page have an average (1.8s ~ 3s) First Contentful Paint (FCP) 5% 2% of loads for this page have a slow (>3s) First Contentful Paint (FCP) 2%
First Input Delay (FID)1ms 99% of loads for this page have a fast (<100ms) First Input Delay (FID) 99% 0% of loads for this page have an average 100ms ~ 300ms) First Input Delay (FID) 0% 0% of loads for this page have a slow (>300ms) First Input Delay (FID) 0%
Interaction To Next Paint (INP)49ms 95% of loads for this page have a fast (<200ms) Interaction To Next Paint (INP) 95% 2% of loads for this page have an average (200ms ~ 500ms) Interaction To Next Paint (INP) 2% 1% of loads for this page have a slow (>500ms) Interaction To Next Paint (INP) 1%
Largest Contentful Paint (LCP)1.3s 92% of loads for this page have a fast (<2500ms) Largest Contentful Paint (LCP) 92% 5% of loads for this page have an average (2500ms ~ 4000ms) Largest Contentful Paint (LCP) 5% 2% of loads for this page have a slow (>4000ms) Largest Contentful Paint (LCP) 2%

Lab Data

Largest Contentful Paint 1.0 s
Largest Contentful Paint marks the time at which the largest text or image is painted. Learn more about the Largest Contentful Paint metric
Timing budget  
Set a timing budget to help you keep an eye on the performance of your site. Performant sites load fast and respond to user input events quickly. Learn more about performance budgets
Speed Index 0.7 s
Speed Index shows how quickly the contents of a page are visibly populated. Learn more about the Speed Index metric
Has a `<meta name="viewport">` tag with `width` or `initial-scale`  
A `<meta name="viewport">` not only optimizes your app for mobile screen sizes, but also prevents . a 300 millisecond delay to user input Learn more about using the viewport meta tag
Time to Interactive 0.7 s
Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric
Total Blocking Time 0 ms
Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds. Learn more about the Total Blocking Time metric
First Meaningful Paint 0.7 s
First Meaningful Paint measures when the primary content of a page is visible. Learn more about the First Meaningful Paint metric
Performance budget  
Keep the quantity and size of network requests under the targets set by the provided performance budget. Learn more about performance budgets
Lazy load third-party resources with facades  
Some third-party embeds can be lazy loaded. Consider replacing them with a facade until they are required. Learn how to defer third-parties with a facade
First Contentful Paint 0.7 s
First Contentful Paint marks the time at which the first text or image is painted. Learn more about the First Contentful Paint metric

Page Speed (Google PageSpeed Insights) - Mobile

80
0-49 50-89 90-100 i

Field Data

Over the last 30 days, the field data shows that this page has a SLOW speed compared to other pages in the Chrome User Experience Report.We are showing the 90th percentile of FCP and the 95th percentile of FID.

Cumulative Layout Shift (CLS)15ms 94% of loads for this page have a fast (<0.01s) Cumulative Layout Shift (CLS) 56% 35% of loads for this page have an average (0.01s ~ 0.025s) Cumulative Layout Shift (CLS) 35% 8% of loads for this page have a slow (>0.025s) Cumulative Layout Shift (CLS) 8%
Time To First Byte (TTFB)599ms 92% of loads for this page have a fast (<800s) Time To First Byte (TTFB) 83% 12% of loads for this page have an average (800s ~ 1800s) Time To First Byte (TTFB) 12% 4% of loads for this page have a slow (>1800s) Time To First Byte (TTFB) 4%
First Contentful Paint (FCP)1.8s 92% of loads for this page have a fast (<1.8s) First Contentful Paint (FCP) 74% 15% of loads for this page have an average (1.8s ~ 3s) First Contentful Paint (FCP) 15% 9% of loads for this page have a slow (>3s) First Contentful Paint (FCP) 9%
First Input Delay (FID)72ms 76% of loads for this page have a fast (<100ms) First Input Delay (FID) 76% 21% of loads for this page have an average (100ms ~ 300ms) First Input Delay (FID) 21% 1% of loads for this page have a slow (>300ms) First Input Delay (FID) 1%
Interactive To Next Paint (INP)598ms 95% of loads for this page have a fast (<200s) Interactive To Next Paint (INP) 21% 44% of loads for this page have an average (200s ~ 500s) Interactive To Next Paint (INP) 44% 34% of loads for this page have a slow (>500s) Interactive To Next Paint (INP) 34%
Largest Contentful Paint (LCP)2.1s 92% of loads for this page have a fast (<2500s) Largest Contentful Paint (LCP) 81% 11% of loads for this page have an average (2500s ~ 4000s) Largest Contentful Paint (LCP) 11% 7% of loads for this page have a slow (>4000s) Largest Contentful Paint (LCP) 7%

Origin Data

All pages served from this origin have an SLOW speed compared to other pages in the Chrome User Experience Report. over the last 30 days.To view suggestions tailored to each page, analyze individual page URLs.

Cumulative Layout Shift (CLS)14ms 62% of loads for this page have a fast (<0.01s) Cumulative Layout Shift (CLS) 62% 28% of loads for this page have an average (0.01s ~ 0.025s) Cumulative Layout Shift (CLS) 28% 9% of loads for this page have a slow (>0.025s) Cumulative Layout Shift (CLS) 9%
Time To First Byte (TTFB)681ms 80% of loads for this page have a fast (<0.8s) Time To First Byte (TTFB) 80% 14% of loads for this page have an average (0.8s ~ 1.8s) Time To First Byte (TTFB) 14% 4% of loads for this page have a slow (>1.8s) Time To First Byte (TTFB) 4%
First Contentful Paint (FCP)2.0s 70% of loads for this page have a fast (<1.8s) First Contentful Paint (FCP) 70% 18% of loads for this page have an average (1.8s ~ 3s) First Contentful Paint (FCP) 18% 10% of loads for this page have a slow (>3s) First Contentful Paint (FCP) 10%
First Input Delay (FID)60ms 99% of loads for this page have a fast (<100ms) First Input Delay (FID) 77% 20% of loads for this page have an average 100ms ~ 300ms) First Input Delay (FID) 20% 1% of loads for this page have a slow (>300ms) First Input Delay (FID) 1%
Interactive To Next Paint (INP)592ms 23% of loads for this page have a fast (<0.2s) Interactive To Next Paint (INP) 23% 43% of loads for this page have an average (0.2s ~ 0.5s) Interactive To Next Paint (INP) 43% 33% of loads for this page have a slow (>0.5s) Interactive To Next Paint (INP) 33%
Largest Contentful Paint (LCP)2.2s 80% of loads for this page have a fast (<2.5s)Largest Contentful Paint (LCP) 80% 12% of loads for this page have an average (2.5s ~ 4s)Largest Contentful Paint (LCP) 12% 7% of loads for this page have a slow (>4s)Largest Contentful Paint (LCP) 7%

Lab Data

Total Blocking Time 20 ms
Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds. Learn more about the Total Blocking Time metric
Performance budget  
Keep the quantity and size of network requests under the targets set by the provided performance budget. Learn more about performance budgets
First Contentful Paint 2.3 s
First Contentful Paint marks the time at which the first text or image is painted. Learn more about the First Contentful Paint metric
First Meaningful Paint 2.4 s
First Meaningful Paint measures when the primary content of a page is visible. Learn more about the First Meaningful Paint metric
Timing budget  
Set a timing budget to help you keep an eye on the performance of your site. Performant sites load fast and respond to user input events quickly. Learn more about performance budgets
Speed Index 2.7 s
Speed Index shows how quickly the contents of a page are visibly populated. Learn more about the Speed Index metric
Has a `<meta name="viewport">` tag with `width` or `initial-scale`  
A `<meta name="viewport">` not only optimizes your app for mobile screen sizes, but also prevents . a 300 millisecond delay to user input Learn more about using the viewport meta tag
Lazy load third-party resources with facades  
Some third-party embeds can be lazy loaded. Consider replacing them with a facade until they are required. Learn how to defer third-parties with a facade
Time to Interactive 2.5 s
Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric
Largest Contentful Paint 4.6 s
Largest Contentful Paint marks the time at which the largest text or image is painted. Learn more about the Largest Contentful Paint metric

Does check-host.cc use compression? ▼

Website compression is the process of reducing the size of website files, such as HTML, CSS, JavaScript, and image files, to improve website performance and load times. Compressing website files can significantly reduce the amount of data that needs to be transferred from the server to the user's browser, resulting in faster page load times and improved user experience. Files on check-host.cc are reduced by 95%.
check-host.cc use br compression.
Original size: 174.23 KB
Compressed size: 8.17 KB
File reduced by: 166.06 KB (95%)

Google Safe Browsing ▼

Google Safe Browsing is a service provided by Google that helps protect users from visiting websites that may contain malicious or harmful content, such as malware, phishing attempts, or deceptive software.
This site is not currently listed as suspicious

MyWot.com Reputation Ratings

MyWOT (short for "My Web of Trust") is a web-based reputation and rating service that provides users with information about the trustworthiness and safety of websites.
Status:
  SAFE

SSL Checker - SSL Certificate Verify ▼

An SSL (Secure Sockets Layer) certificate is a digital certificate that establishes a secure encrypted connection between a web server and a user's web browser. It provides authentication and encryption, ensuring that data transmitted between the server and the browser remains private and protected. check-host.cc supports HTTPS.
 check-host.cc supports HTTPS
     
Verifying SSL Support. Please wait...
Common Name: check-host.cc
Organization:
Location:
Issuer: GTS CA 1P5
Valid from: Jan 15 21:17:47 2024 GMT
Valid until: Apr 14 21:17:46 2024 GMT
Authority: CA:FALSE
Keysize: 2048 Bits
Common Name: GTS CA 1P5
Organization: Google Trust Services LLC
Location: US
Issuer: GTS Root R1
Valid from: Aug 13 00:00:42 2020 GMT
Valid until: Sep 30 00:00:42 2027 GMT
Authority: CA:TRUE
Keysize: 2048 Bits
Common Name: GTS Root R1
Organization: Google Trust Services LLC
Location: US
Issuer: GlobalSign Root CA
Valid from: Jun 19 00:00:42 2020 GMT
Valid until: Jan 28 00:00:42 2028 GMT
Authority: CA:TRUE
Keysize: 4096 Bits

Verify HTTP/2 Support ▼

HTTP/2 (Hypertext Transfer Protocol version 2) is a major revision of the HTTP protocol, which is the foundation of data communication on the World Wide Web. It was developed as an improvement over the previous HTTP/1.1 version to enhance web performance and efficiency.
 check-host.cc supports HTTP/2
     
Verifying HTTP/2.0 Support. Please wait...

Http Header ▼

HTTP headers are extra portions of records despatched among a consumer (which include an internet browser) and a server at some stage in an HTTP request or response. They offer instructions, metadata, or manipulate parameters for the conversation among the consumer and server. 
date: Fri, 09 Feb 2024 10:21:01 GMT
content-type: text/html; charset=UTF-8
vary: Accept-Encoding
access-control-allow-origin: https://docs.check-host.cc
access-control-allow-credentials: true
access-control-allow-methods: GET, POST, OPTIONS
access-control-allow-headers: DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type
x-cache: HIT
x-frame-options: DENY
x-content-type-options: nosniff
x-xss-protection: 1; mode=block
l7-filter: FW01
last-modified: Fri, 09 Feb 2024 09:45:18 GMT
cache-control: max-age=691200
cf-cache-status: HIT
report-to: {"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v3?s=bKOV2aOH67s9KjM%2BxV54PWLV3RYd5kLh19cAWa%2FnYnTBYJgAAD%2BenR1IqnvzxBG5%2FviFTYtwjtQxjJ2iJ9fi%2BJWGLXBNXPxq5p%2FDoxFrRDofi9gOo9NQ6gbQaZj5KcYT"}],"group":"cf-nel","max_age":604800}
nel: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
strict-transport-security: max-age=31536000; includeSubDomains; preload
server: cloudflare
cf-ray: 852b6215eb96233e-ORD
content-encoding: br
alt-svc: h3=":443"; ma=86400

DNS Lookup ▼

DNS entries (Domain Name System) are a critical component of the Internet infrastructure. They act as directories that translate human-readable domain names (such as example.com) to machine-readable IP addresses. DNS records are stored on DNS servers and help forward internet traffic efficiently.
Type Ip Target/Txt TTL
HINFO 3600
AAAA 2606:4700:3037::6815:1c4e 220
AAAA 2606:4700:3032::ac43:90e3 220
A 104.21.28.78 220
A 172.67.144.227 220
NS fay.ns.cloudflare.com 172720
NS stan.ns.cloudflare.com 172720

Whois Lookup ▼

Domain WHOIS is a public database that provides information about domain names, including registered owners, contact information, domain registrars, registration and expiration dates, name servers, and other relevant information. Domain registration for this website began on November 20, 2021 and will expire on November 20, 2030 if not renewed. This website is now assigned through the registrar OVH sas. The WHOIS data for this website's domain was last updated on January 1, 2023.
Domain Created:
2021-11-20
Domain Expires:
2030-11-20
Domain Updated:
2023-01-01
Domain Age:
3 years 3 months 14 days
Domain Registrar:
OVH sas
WhoIs:
 

   Domain Name: CHECK-HOST.CC
   Registry Domain ID: 167044666_DOMAIN_CC-VRSN
   Registrar WHOIS Server: whois.ovh.com
   Registrar URL: http://www.ovh.com
   Updated Date: 2023-01-01T16:20:29Z
   Creation Date: 2021-11-20T20:21:05Z
   Registry Expiry Date: 2030-11-20T20:21:05Z
   Registrar: OVH sas
   Registrar IANA ID: 433
   Registrar Abuse Contact Email: email
   Registrar Abuse Contact Phone: +33.972101007
   Domain Status: clientDeleteProhibited https://icann.org/epp#clientDeleteProhibited
   Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited
   Name Server: FAY.NS.CLOUDFLARE.COM
   Name Server: STAN.NS.CLOUDFLARE.COM
   DNSSEC: unsigned
   URL of the ICANN Whois Inaccuracy Complaint Form: https://www.icann.org/wicf/
>>> Last update of WHOIS database: 2024-02-09T10:22:12Z