HTML integration of image URI for validation

Question

I have a problem with validation of my site with, mainly because of data/images base64 URIs.

Here is the diagnostic of https://html5.validator.nu/

Error: Malformed byte sequence: e9.
At line 2, column 259

(etc.)

As for https://validator.w3.org/ it simply says it cannot analyze the site.

What I have in my website is:

<a class=imgfr onclick='toggle("fr")' title=Fran&ccedil;ais>
<img class=imfr 
src="data:image/png,base64,iVBORw0KGgoAAAANSUhEUgAAAB4AAAAUCAIAAAAVyRqTAAAAjklEQVQ4jWM4cupJy7Qz2NGsM0+evfny6QsIfcMgHz15MqnnTV8LdnTqCEPLrCMsRnNwoSv33vz59wc7unbljpIIGPFgkkDTGYCuo8xoLOYCSaCHRl09VFytNurqUVcPpKuxG00VV2MPkGHpah4zylwNqsBmHQFXV5gkuAL79gU7glVgQPIJuNJCZgArMAD4cQgh3IjAhAAAAABJRU5ErkJggg==" 
title=Francais alt=Fran&ccedil;ais>
</a>

The document is declared as only

<!Doctype html>

I have in the head:

<meta content="text/html; charset=utf-8" http-equiv=Content-Type>

Obviously I have checked several Q/A here like Embedding Base64 Images or How to display Base64 images in HTML, however these do not provide the answers to my question.

Also the one validator which works tells me that my http-equiv below have bad value attribute:

<meta http-equiv="window-target" content="_top">
<meta http-equiv=Expires content="Sat, 26 Jul 1997 05:00:00 GMT">
<meta http-equiv=Pragma content="no-cache must-revalidate">

What should I do?

In order to reply to a comment which does not show anymore (???) the colon and no-space were there , it was my mistake in copying... Also, although the validator tells me that my attribute value for http-equiv are invalid, we can find lots of resources on the web which tell differently : http://cristian.sulea.net/blog.php?p=2014-01-14-disable-browser-caching-with-meta-html-tags or https://wp-mix.com/disable-caching-html/ for instance tell it is correct.... — jean, Dec 15 '17 at 13:10

score 0 · Answer 1 · edited Mar 09 '23 at 18:34

Some things were my mistakes... I did not read precisely enough the diagnostic of the w3c evaluator.

The diagnosis

Error malformed sequence

was not related to the images URI as I thought, but to accented characters

Secondly, I received advice on another forum that, although there are a good number of blogs and books and so on which support/advertise on following the advice of inserting the meta tags I mentioned in the original post, as they are not recommended anymore - even worse, they are altogether discarded in the HTML as of last year at the minimum - I should better follow the norm, even if some discussions are still ongoing.

HTML integration of image URI for validation

1 Answers1