c21.com.cn
二手房源_租房网_买房网_房产网-C21在线全球真房源【21世纪不动产】
Last scanned Jul 27, 2026, 9:43 AM · 1 view
Overall score
Fair
Summary
C21在线提供最新、最真实、海量全面的房源信息为目标,打造二手房源,租房网,买房网,房产网信息数据库服务、小区房价服务、多图房源服务、地图找房服务等。为用户… This website uses Nuxt hosted on ALIBABA-CN-NET - Hangzhou Alibaba Advertising Co.,Ltd., CN. SEO is fair (55/100) and accessibility is good (80/100). Security scores good (75/100) and performance excellent (100/100). Top issue: Title longer than 60 characters.
C21在线提供最新、最真实、海量全面的房源信息为目标,打造二手房源,租房网,买房网,房产网信息数据库服务、小区房价服务、多图房源服务、地图找房服务等。为用户提供全面线上线下交易流程指导,权威二手房的服务体验平台。
- China
- Hosted on ALIBABA-CN-NET - Hangzhou Alibaba Advertising Co.,Ltd., CN
Top issues to fix
13 issues found · 2 high priority
Missing Content-Security-Policy header
SecurityAdd a CSP to control which sources can run scripts — the strongest single defense against XSS.
No H1 heading found
SEOAdd exactly one H1 describing the page's main topic — it anchors the document outline for search engines and screen readers.
TLS certificate expires in 20 days
SecurityRenew soon or enable auto-renewal to avoid a browser-warning outage.
Missing X-Content-Type-Options header
SecurityAdd X-Content-Type-Options: nosniff to stop MIME-sniffing attacks.
Missing X-Frame-Options header
SecurityAdd X-Frame-Options (or a CSP frame-ancestors rule) to prevent clickjacking via hidden iframes.
Title longer than 60 characters
SEOShorten the title to under 60 characters so search results don't truncate it.
+7 more issues — details in the sections below.
SEO
7 issue(s) found
Performance
170 ms
Security
HTTPS & header checks
Accessibility
2 issue(s) found
Organization
Company details published in this site's own structured data.
C21在线提供最新、最真实、海量全面的房源信息为目标,打造二手房源,租房网,买房网,房产网信息数据库服务、小区房价服务、多图房源服务、地图找房服务等。为用户提供全面线上线下交易流程指导,权威二手房的服务体验平台。
Meta tags
- Title
- 二手房源_租房网_买房网_房产网-C21在线全球真房源【21世纪不动产】
- Description
- C21在线提供最新、最真实、海量全面的房源信息为目标,打造二手房源,租房网,买房网,房产网信息数据库服务、小区房价服务、多图房源服务、地图找房服务等。为用户提供全面线上线下交易流程指导,权威二手房的服务体验平台。
- Canonical
- Language
- Charset
- utf-8
- Viewport
- width=device-width, initial-scale=1
- Robots meta
- Manifest
Technologies
Detected frameworks, languages, and tools.
Hosting & CDN
- Hosting provider
- ALIBABA-CN-NET - Hangzhou Alibaba Advertising Co.,Ltd., CN
- CDN provider
- —
- IP address
- 120.55.233.209
- ASN
- AS37963 (ALIBABA-CN-NET - Hangzhou Alibaba Advertising Co.,Ltd., CN)
DNS records
| Type | Value |
|---|---|
| A |
|
| AAAA | — |
| MX |
|
| TXT |
|
| NS |
|
| CAA | — |
| CNAME | — |
| IPv6 support | No |
TLS / SSL certificate
- Version
- TLS 1.3
- Issuer
- DigiCert Inc
- Subject
- *.c21.com.cn
- Valid from
- Aug 12, 2025
- Valid to
- Aug 16, 2026
- Days until expiry
- 20
- SAN domains
- c21.com.cn, *.c21.com.cn
Security headers
- Strict-Transport-SecurityEnabled
- Content-Security-PolicyMissing
- X-Frame-OptionsMissing
- X-Content-Type-OptionsMissing
- Referrer-PolicyMissing
- Permissions-PolicyMissing
Compression: gzip · 0 cookie(s) observed
Content & assets
Headings
H1 0 · H2 0 · H3 0
Links
4 internal · 11 external · 5 broken
Images
12 total · 2 missing alt
Scripts / Styles
9 scripts · 1 stylesheets
JS / CSS size
534 KB · 71.6 KB
Page size
9.5 KB
Robots.txt & Sitemap
- robots.txt
- Not found
- Disallow rules
- 0
- sitemap.xml
- Not found
- URLs in sitemap
- 0
SEO issues
- Title longer than 60 characters
- Meta description longer than 160 characters
- Missing canonical link
- No H1 heading found
- No structured data (JSON-LD) found
- robots.txt not found
- sitemap.xml not found
Accessibility issues
- No H1 heading found
- Missing <html lang> attribute
Scan details
- Requested URL
- https://c21.com.cn
- Final URL
- https://c21.com.cn
- HTTP status
- 200
- HTTP version
- HTTP/2
- Response time
- 170 ms
- HTML size
- 9.5 KB
- Redirect chain
- https://c21.com.cn
See something wrong on this report? Request a correction
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Frequently asked questions
- What technology does c21.com.cn use?
- c21.com.cn is built with Vue.js, Nuxt.
- Is c21.com.cn secure (HTTPS)?
- Yes. c21.com.cn uses TLS 1.3 with a certificate issued by DigiCert Inc, valid until Aug 16, 2026.
- Who hosts c21.com.cn?
- c21.com.cn is hosted on ALIBABA-CN-NET - Hangzhou Alibaba Advertising Co.,Ltd., CN.
- What is c21.com.cn's SEO score?
- c21.com.cn scored 55/100 for SEO in the latest analysis (fair).
- What is c21.com.cn's overall website score?
- c21.com.cn has an overall SiteGraph score of 76/100, combining SEO, performance, security, and accessibility.
OpenGraph & Twitter Card
OpenGraph
Twitter Card