Would you like to switch to the entire w3.org domain? There are 4,230,897,820 external backlinks.
Trust Flow
Link Quality
How would you like to start?
Citation Flow
Link Volume

The W3C Markup Validation Service

In the last 90 days In the last 5 years

Fresh - External


Incoming links from other websites, excludes supplemental

Fresh - Referring

500K - 1M

Unique domains linking to this site. Breakdown

Fresh - Referring


Unique IPs hosting referring domains

Fresh - Referring


Unique Class-C subnets

Historic - External


Incoming links from other websites

Subscribers get Referring Domain, IP and Subnet values for all websites, and Pro+ accounts get Historic Index Plans & Pricing

Outbound Links

9 Internal
2 External
11 Total Outlinks
2 Ext Domains
(Average per Crawled Page)


Crawled URLs 3,903
Indexed URLs 64,050,277
Educational Ref. Backlinks 14,069,336
Governmental Ref. Backlinks 69,944,519
Educational Ref. Domains 4,052
Governmental Ref. Domains 4,670
IP Address

Link Profile

Available to subscribers

Get yours now


A report of the detected language for each page on this domain, and the languages of incoming anchor texts.

Incoming Languages

2,176,038,152 checked backlinks

  •   41.5% en English
  •   13.4% de German
  •   8% it Italian
  •    6% fr French
  •    4.4% es Spanish/Castilian
  •    4% ru Russian
  •    2.5% pl Polish
  •    2.3% cs Czech
  •    0.8% nl Dutch/Flemish
  •    0.6% zh Chinese
  •    16.5% OTH Other

Site Languages

555 language-detected crawled URLs

  •   99.4% en English

Topical Trust Flow

A measure of how close you are to the most trusted websites in almost one thousand categories.

Topical Trust Flow is available on all websites, to all subscribers, even on our lowest-price plan.

Plans & Pricing

To see a live example of our amazing Trust Flow categorisation, check out example.com

Referring Domains Breakdown

Referring Domains

This chart shows the number of Referring Domains reviewed every day.

Available to subscribers Plans & Pricing

Anchor Text

See more results on the Anchor Text tab, where you can drill down into each keyword and find the Referring Domains and External Backlinks that use that Keyword.

# Anchor Text Referring Domains External Backlinks
Total Deleted NoFollow
1 valid xhtml 1.0 transitional Subscribe
106,326,580 1,574,016 13,001,738
2 xhtml Subscribe
543,592,273 5,588,889 60,406,551
3 valid xhtml Subscribe
93,199,036 1,314,326 23,753,457
4 valid xhtml 1.0 strict Subscribe
48,187,816 510,477 5,219,875
5 valid html 4.01 transitional Subscribe
33,948,072 685,420 1,675,276
6 valid html5 Subscribe
327,905,246 1,322,560 322,225,577
7 valid xhtml 1.0! Subscribe
56,070,573 582,095 6,170,700
8 valid html 4.01! Subscribe
15,079,444 144,541 679,173
9 xhtml 1.0 Subscribe
44,707,362 597,286 5,089,272

The above chart may have cropped text due to size restrictions, for full details visit the Anchor Text tab. We explain how this is created in the FAQs.

Do you control w3.org? Verify that you own the domain and get extended free Site Explorer Sign Up for FREE