Prefer charset declaration in HTML meta tag or HTTP header?

Question

I'm parsing a lot of sites. All works fine, I'm reading also charset declarations to convert encodings. Now I've a problem with http://celleheute.de/sonntagsfuhrung-3/.

The HTML meta tag says, that the content is encoded as ISO-8859-2, but the HTTP header says, it's UTF-8. And really, the content is UTF encoded, so when my parser tries to convert the content to ISO it will break some chars.

Now my question is, which declaration should I prefer? Should I ignore meta tags, when I can find the declaration in HTTP header or vice versa? What will most web browsers do?

Answer 1

To understand what modern browsers do, you should start reading at http://w3c.github.io/html/syntax.html#determining-the-character-encoding

Steps one and two are most relevant to the question. They say

1. If the user has explicitly instructed the user agent to override the document's character encoding with a specific encoding, optionally return that encoding with the confidence certain and abort these steps.

2. If the transport layer specifies an encoding, and it is supported, return that encoding with the confidence certain, and abort these steps.

which means that the real HTTP header takes precedence over everything except user over-ride.

Beyond that it can get complex. A byte order mark, can for example, take precedence over the meta tag.

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UPDATE: Since this answer was written, the spec changed (around mid-2012) so that the byte order mark now takes precedence over the HTTP header.