2023: 0 of the Global Top 100 Websites Use Valid HTML · Jens Oliver Meiert

By admin

2023
DATE

:

0
CARDINAL

of the Global Top 100 Websites Use Valid HTML

Let’s dive right in: Nothing changed compared to

last year
DATE

—none of the

100
CARDINAL

most-visited websites globally uses HTML in full conformance with the HTML specification.

The following data gives an impression of precision that is greater than warranted. The point of this

annual
DATE

analysis is to check on full HTML conformance (absence of markup errors); that is, CSS conformance checks are a bonus, and the specific error counts don’t matter for the purpose of telling conformance or non-conformance, either. I’m providing the data for further study, and for comparability to

previous years
DATE

.

Analysis

After

2021 and 2022
DATE

, I used the

annual
DATE

update of the

Ahrefs
ORG

Top

100
CARDINAL

websites to check the homepages of these websites on HTML conformance.

For that purpose I took all the respective URLs, prepared HTML and CSS validation URLs, and documented the error counts of the

200
CARDINAL

tests in a spreadsheet:

Figure: The most-frequented websites and their use of HTML and

CSS
ORG

according to the specifications.

HTML Conformance in

2023
DATE

0 of the

100
CARDINAL

websites have

0
CARDINAL

HTML conformance errors.


3
CARDINAL

(

Adobe
ORG

,

Speedtest
ORG

, and

Spotify
ORG

) were very close to conformance, with

1
CARDINAL

error each.

14
CARDINAL

more had a single-digit number of issues.


37
CARDINAL

were far away from conformance with any specification (

100
CARDINAL

or more errors).

The average number of

HTML
ORG

errors is

132.14
CARDINAL

.

The HTML errors median is

62
DATE

.

(The mode is

23
CARDINAL

.)

CSS Conformance in

2023
DATE

The W3C CSS validator needs updating. There appear to be many false positives (and a suspicion of false negatives), raising concern that the results aren’t practically useful anymore (perhaps not even for ballpark numbers). CSS conformance isn’t as critical as HTML conformance, but it’s important for us to have a reliable CSS validator.


12
CARDINAL

of

94
CARDINAL

tested websites have 0 CSS conformance errors. (

6
CARDINAL

websites could not be checked.)


34
CARDINAL

were close to conformance, with a single-digit number of errors.


7
CARDINAL

were far away (

100
CARDINAL

or more errors, with

one
CARDINAL

site containing

more than 1,000
CARDINAL

errors).

The average number of

CSS
ORG

errors is

46.79
CARDINAL

.

The median is

10.5
CARDINAL

.

(The mode is

0
CARDINAL

.)

HTML and CSS Conformance over Time

We need to test more websites to make this significant, but given that this has been the

third
ORDINAL

analysis, here is how error counts developed over

the years
DATE

:


2021 2022
DATE

2023 HTML ø

125.22
CARDINAL

errors ø

125.63
CARDINAL

errors → ø

132.14
DATE

errors ↗

2
CARDINAL

homepages without errors

0
CARDINAL

homepages without errors ↘

0
CARDINAL

homepages without errors →

CSS ø 48.40
LAW

errors ø

26.33
CARDINAL

errors ↓ ø

46.79
CARDINAL

errors ↑

3
CARDINAL

homepages without errors

13
CARDINAL

homepages without errors ↑

12
CARDINAL

homepages without errors →

Interpretation

I think the results speak for themselves.

Personally, I’m outspoken about the usefulness of conformance—I think it’s foundational for our field, that it should be a hiring criterion, and that it could unite us to tackle other important challenges. (If you’re interested, I also run an ebook series—check out the latest edition—explaining and promoting valid, minimal HTML.)

While that’s me, even during

the years
DATE

of

the Web Standards Project
ORG

(

1998–2013
DATE

), our field has neither accepted this nor any other quality standard for its output.

We can use every developer to improve this—lead by example and ship valid code—, but going by the data, there’s no change in sight.

About Me

I’m

Jens
PERSON

, and I’m an engineering lead and author. I’ve worked as a technical lead for companies like

Google
ORG

, I’m close to W3C and

WHATWG
PERSON

, and I write and review books for

O’Reilly
ORG

and

Frontend Dogma
ORG

. I love trying things, not only in web development, but also in other areas like philosophy. Here on meiert.com I share some of my views and experiences.

If you have a question or suggestion about what I write, please leave a comment (if available) or a message. Thank you!