21ic.com ▷ 21IC电子网 - 电子工程师的优选网站

Quick Summary

Online Status

Online

Server IP address resolved: Yes
Http response code: 200
Response time: 1.61 sec.
Last Checked: 08/18/2025

21ic.com traffic volume is 25,568 unique daily visitors and their 69,033 pageviews. The web value rate of 21ic.com is 1,209,143 USD. Each visitor makes around 2.89 page views on average.

By Alexa's traffic estimates 21ic.com placed at 47,938 position over the world, while the largest amount of its visitors comes from China, where it takes 1,312 place.

Perfect for 21ic.com that their data center (provided by company company CT-HUNAN-HENGYANG-IDC Hengyang, CN) is located in China, as that empowers most of the visitors to reduce the page load time. See the list of other web pages hosted by CT-HUNAN-HENGYANG-IDC Hengyang, CN.

21ic.com registered under .COM top-level domain. Check other websites in .COM zone.

The last verification results, performed on (October 13, 2024) 21ic.com show that 21ic.com has an expired wildcard SSL certificate issued by DigiCert Inc (expired on February 14, 2025). Click “Refresh” button for SSL Information at the Safety Information section. Check the list of websites using SSL certificates issued by DigiCert Inc.

In accordance with Google Safe Browsing, Google Safe Search, Symantec and Web of Trust 21ic.com is pretty a safe domain.

Relying Google MobileFriendly test 21ic.com is well optimized for mobile and tablet devices, however web page loading speed may be improved.

21ic.com General Information

Global Rank

10,532

Average Load Time

1.11sec

Links In Count

676

Website Value

$1.1 M

Audience Geography. Where are 21ic.com visitors located?

Country	Visitors
China CN	96.8%
Taiwan TW	0.7%
Other	2.5%

Country	Pageviews
China CN	98.2%
Taiwan TW	0.8%
Other	1%

Country	Rank
China CN	1312
Taiwan TW	13141

Where do visitors go on 21ic.com?

Subdomain	Pageviews
bbs.21ic.com	59.86%
21ic.com	16.76%
dl.21ic.com	4.58%
my.21ic.com	3.69%
edu.21ic.com	3.56%
project.21ic.com	2.81%
tj.21ic.com	2.11%
search.21ic.com	1.47%
power.21ic.com	1.37%
other	3.8%

Subdomain	Pageviews per User
tj.21ic.com	4
search.21ic.com	3
project.21ic.com	3
edu.21ic.com	3
bbs.21ic.com	2.7
dl.21ic.com	2.1
my.21ic.com	1.8
21ic.com	1.8
huodong.21ic.com	1
embed.21ic.com	1
other	0.5

Subdomain	Reach
bbs.21ic.com	68%
21ic.com	29.16%
dl.21ic.com	6.91%
my.21ic.com	6.46%
power.21ic.com	3.89%
edu.21ic.com	3.83%
embed.21ic.com	2.74%
project.21ic.com	2.62%
huodong.21ic.com	2.24%
tj.21ic.com	1.86%
other	1.53%

How popular is 21ic.com?

Period	Global Rank	Global Rank Delta
past 3 months	10532	-4212
past month	11793	964
past week	17099	6364
yesterday	5949	-38558

Days	Pageviews Rank	Pageviews Rank Delta	Pageviews per Million	Pageviews per Million Delta	Pageviews per User	Pageviews per User Delta
90	12795	-4335	578	34%	2.7	-3.62%
30	13007	-117	57	0.4%	3.1	20%
7	17488	6872	42	-40.62%	3.5	-3.57%
1	4152	-74330	18	2000%	6.1	300%

Days	Reach Rank	Reach Rank Delta	Reach per Million	Reach per Million Delta
90	10330	-4473	81	39%
30	12292	1525	67	-12.64%
7	18426	6772	44	-38.4%
1	7445	-30024	110	400%

21ic.com Safety Information

Overview

Last Updated: 08/18/2025

Overall result - 21ic.com is safe.

We gather website safety and reputation data and compare it with available third-party sources so we calculate own safety and trustworthiness rate based on information that we get.

Norton Connect Safe

Last Updated: 03/21/2025

21ic.com is safe.

Norton ConnectSafe evaluates 21ic.com for any unsafe and insecure content. The results are critical for families with young children.

Google Safe Search

Last Updated: 02/07/2019

21ic.com is safe.

SafeSearch is used as a parental control tool to filter out any inappropriate for your children search results on your devices: phones, tablets or personal computers.

Google Safe Browsing

Last Updated: 01/09/2019

21ic.com is safe.
Malware: not found.
Phishing: not detected.
Unwanted software: not found.
Harmfull applications: not found.

Google Safe Browsing notifies when websites are compromised by malicious actors. These protections work across Google products and provide a safer online experience.

Site Advisor

Last Updated: 02/22/2021

21ic.com is safe.

McAfee assesses 21ic.com for a meaningful set of security threats. Featured dangers from annoying pop-ups to hidden Trojans, that can steal your identity, will be revealed. McAfee does not analyze 21ic.com for mature or inappropriate content, only security checks are evaluated.

Web of Trust

Last Updated: 01/09/2019

21ic.com child safety is very good.

The WOT calculates reputation of the 21ic.com. This reputation system receives ratings from users and information from third-party sources, assesses the 21ic.com for safety features and confirms, whether 21ic.com is suitable for children.

SSL Information

SSL Checker Tool

Domain	*.21ic.com
Issuer Organization	DigiCert Inc
Issuer	Encryption Everywhere DV TLS CA - G1
Algorithm	RSA-SHA256
Valid form	01/29/2024
Expiration	02/14/2025
Signed	Certificate is not self signed
Additional Domains	*.21ic.com 21ic.com

21ic.com Server Information

Server Location

Geolocation Tool

ASN Information

ASN Lookup Tool

ASN ID: 63838
ASN Title: CT-HUNAN-HENGYANG-IDC Hengyang, CN

Last Update: 04/11/2025

ASN Whois

#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/whois_tou.html
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/whois_reporting/index.html
#
# Copyright 1997-2018, American Registry for Internet Numbers, Ltd.
#

ASNumber: 63488 - 64197
ASName: IANA-RSVD
ASHandle: AS63488
RegDate: 2013-06-07
Updated: 2013-06-07
Ref: https://rdap.arin.net/registry/autnum/63488

OrgName: Internet Assigned Numbers Authority
OrgId: IANA
Address: 12025 Waterfront Drive
Address: Suite 300
City: Los Angeles
StateProv: CA
PostalCode: 90292
Country: US
RegDate:
Updated: 2012-08-31
Ref: https://rdap.arin.net/registry/entity/IANA

OrgTechHandle: IANA-IP-ARIN
OrgTechName: ICANN
OrgTechPhone: +1-310-301-5820
OrgTechEmail: abuse@iana.org
OrgTechRef: https://rdap.arin.net/registry/entity/IANA-IP-ARIN

OrgAbuseHandle: IANA-IP-ARIN
OrgAbuseName: ICANN
OrgAbusePhone: +1-310-301-5820
OrgAbuseEmail: abuse@iana.org
OrgAbuseRef: https://rdap.arin.net/registry/entity/IANA-IP-ARIN

#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/whois_tou.html
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/whois_reporting/index.html
#
# Copyright 1997-2018, American Registry for Internet Numbers, Ltd.
#

21ic.com Domain Name Information

WHOIS

WHOIS Lookup Tool

Domain Whois

Domain Name: 21IC.COM
Registry Domain ID: 17040411_DOMAIN_COM-VRSN
Registrar WHOIS Server: grs-whois.hichina.com
Registrar URL: http://www.net.cn
Updated Date: 2024-01-04T07:34:20Z
Creation Date: 2000-01-10T02:41:29Z
Registry Expiry Date: 2026-01-10T02:41:29Z
Registrar: Alibaba Cloud Computing (Beijing) Co., Ltd.
Registrar IANA ID: 420
Registrar Abuse Contact Email: DomainAbuse@service.aliyun.com
Registrar Abuse Contact Phone: +86.95187
Domain Status: ok https://icann.org/epp#ok
Name Server: DNS1.HICHINA.COM
Name Server: DNS2.HICHINA.COM
DNSSEC: unsigned
URL of the ICANN Whois Inaccuracy Complaint Form: https://www.icann.org/wicf/
>>> Last update of whois database: 2024-09-10T21:59:46Z

DNS Records

DNS Lookup Tool

Host	A Record	TTL
21ic.com	182.92.121.124	3600

Host	MX Record	Priority	TTL
21ic.com	mx2.qiye.aliyun.com	10	600
21ic.com	mx3.qiye.aliyun.com	15	600
21ic.com	mx1.qiye.aliyun.com	5	600

Host	NS Record	TTL
21ic.com	dns2.hichina.com	86400
21ic.com	dns1.hichina.com	86400

Host	TXT Record	TTL
21ic.com	v=spf1 include:spf.qiye.aliyun.com -all	600

dns1.hichina.com
TTL: 600
Email address: hostmaster.hichina.com
Serial: 2024082817
Refresh: 3600
Retry: 1200
Expire: 86400
Minimum: 600

21ic.com HTML Validation

HTML Validation Tool

Errors

Legacy encoding “gbk” used. Documents must use UTF-8.

Almost standards mode doctype. Expected “<!DOCTYPE html>”.

Bad value “gb2312” for attribute “lang” on element “html”: The language subtag “gb2312” is not a valid language subtag.

Bad value “text/html; charset=gb2312” for attribute “content” on element “meta”: “charset=” must be followed by “utf-8”.

A “meta” element with an “http-equiv” attribute whose value is “X-UA-Compatible” must have a “content” attribute with the value “IE=edge”.

CSS: “_top”: Parse Error.

The “marginheight” attribute on the “iframe” element is obsolete. Use CSS instead.

The “marginwidth” attribute on the “iframe” element is obsolete. Use CSS instead.

The “frameborder” attribute on the “iframe” element is obsolete. Use CSS instead.

The “scrolling” attribute on the “iframe” element is obsolete. Use CSS instead.

An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.

Element “p” not allowed as child of element “span” in this context. (Suppressing further errors from this subtree.)

Duplicate ID “power_nav”.

The “font” element is obsolete. Use CSS instead.

Element “img” is missing required attribute “src”.

Element “div” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)

Element “h2” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)

Element “input” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)

Attribute “value” not allowed on element “input” at this point.

Element “input” is missing required attribute “alt”.

Element “span” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)

No space between attributes.

Element “ul” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)

Element “div” not allowed as child of element “span” in this context. (Suppressing further errors from this subtree.)

The “width” attribute on the “table” element is obsolete. Use CSS instead.

The “cellspacing” attribute on the “table” element is obsolete. Use CSS instead.

The “cellpadding” attribute on the “table” element is obsolete. Use CSS instead.

The “border” attribute on the “table” element is obsolete. Use CSS instead.

The “align” attribute on the “div” element is obsolete. Use CSS instead.

Attribute “cellspace” not allowed on element “table” at this point.

The “align” attribute on the “table” element is obsolete. Use CSS instead.

The “valign” attribute on the “td” element is obsolete. Use CSS instead.

The “height” attribute on the “td” element is obsolete. Use CSS instead.

The “width” attribute on the “td” element is obsolete. Use CSS instead.

Stray end tag “tr”.

The “align” attribute on the “td” element is obsolete. Use CSS instead.

Element “h3” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)

No “p” element in scope but a “p” end tag seen.

Stray end tag “a”.

Element “img” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)

Element “dl” is missing a required instance of one or more of the following child elements: “dd”.

End tag for “body” seen, but there were unclosed elements.

Unclosed element “div”.

Warnings

The “type” attribute is unnecessary for JavaScript resources.

The “language” attribute on the “script” element is obsolete. You can safely omit it.

The “border” attribute is obsolete. Consider specifying “img { border: 0; }” in CSS instead.

The first occurrence of ID “power_nav” was here.

The document is not mappable to XML 1.0 due to two consecutive hyphens in a comment.

The “name” attribute is obsolete. Consider putting an “id” attribute on the nearest container instead.

A table row was 27 columns wide and exceeded the column count established by the first row (9).

21ic.com Desktop Insights

Last tested: 02/01/2018

Desktop

Desktop Speed

42%

Optimize images

Leverage browser caching

Enable compression

Eliminate render-blocking JavaScript and CSS in above-the-fold content

Minify JavaScript

Minify HTML

Minify CSS

Desktop Resource Breakdown

Total Resources	164
Number of Hosts	15
Static Resources	125
JavaScript Resources	26
CSS Resources	4

21ic.com Mobile Insights

Last tested: 05/30/2017

Mobile

Mobile Usability

83%

Size tap targets appropriately

Mobile Speed

53%

Enable compression

Avoid landing page redirects

Eliminate render-blocking JavaScript and CSS in above-the-fold content

Minify JavaScript

Leverage browser caching

Optimize images

Minify CSS

Minify HTML

Mobile Resource Breakdown

Total Resources	43
Number of Hosts	13
Static Resources	23
JavaScript Resources	19
CSS Resources	1

21ic.com Typos

www.21ic.com
www.21ic.net
www.21ic.org
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www.21ic.biz
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www.21i.com
www.21ix.com
www.21icx.com
www.21ixc.com
www.21id.com
www.21icd.com
www.21idc.com
www.21if.com
www.21icf.com
www.21ifc.com
www.21iv.com
www.21icv.com
www.21ivc.com
www.21ic.con

21ic.com 21IC电子网 - 电子工程师的优选网站

21IC电子网，电子工程师的优选网站(嵌入式,单片机,DSP,EDA,测试测量,元器件,医疗电子,智能电网)

Quick Summary

21ic.com General Information

21ic.com Safety Information

21ic.com Server Information

21ic.com Domain Name Information

21ic.com HTML Validation

21ic.com Desktop Insights

21ic.com Mobile Insights

21ic.com Nearest Competitors

21ic.com Typos