<h1> or <h5>?

Is there really a difference?

[badtigger]

Is there really a big difference between <h1> and <h5>?
And is there any proof of this?

[Archmaille]

I really have no proof, but I would say that there is most definitely a difference. I sometimes use <h1> at the top of a page, then later on for sub-catagories a <h2> This is what the heading tags are intended for, and what search engines look for.

Multiple <h1> tags usually set off a red flag for search engines (not that you were planning on using them) but I don't know for sure, I have no proof that a <h1> tag is more powerful than a <h5> tag.

[grandpa]

And is there any proof of this?

From the W3C Recommendations Page

There are six levels of headings from H1 (the most important) to H6 (the least important).