I just ran my site, www.doubledogpress.com, through http://validator.w3.org/check and found a number of errors and warnings. Most were of the form <br /> but others were invalid attributes and the like. Will these prevent crawlers from successfully indexing my web site?

RON

Nope.

It doesnt stop indexing, just that it increases the parsing time for bots. so its good to minimize those syntax errors.

No it doesn't.

crawlers don't even LOOK at the code. the source is read from the server and streamed back to the datacentre that requested the page.

Originally Posted by DoubleDog

I just ran my site, www.doubledogpress.com, through http://validator.w3.org/check and found a number of errors and warnings. Most were of the form <br /> but others were invalid attributes and the like. Will these prevent crawlers from successfully indexing my web site?

RON

Well, these errors doesn't create problem in indexing but still you should correct them.

I think only to many broken links would prevent crawlers from deep indexing your sites. Even Google itself would not past all validations.

Nope! Broken links do NOT stop crawlers from "indexing" sites

Originally Posted by chrishirst

No it doesn't.

crawlers don't even LOOK at the code. the source is read from the server and streamed back to the datacentre that requested the page.

I will disagree with you on that.

Pages with syntax error takes little more time to render on the browsers. Bots work similar ways. IMO.

They don't

Bots do NOT render code, they are NOT visual useragents.

BTW

If you want to see what bots see, download WebBog and look at some pages.

Here's something that may be helpful: Why doesn't google.com validate?
It's an indirect answer to your question because he also explains why they don't care if websites they crawl validate.

Those HTML errors do not prevent crawlers. They don't really care about syntax errors.

Originally Posted by chrishirst

Nope! Broken links do NOT stop crawlers from "indexing" sites

But we must be careful about broken links and must fix them if they exist as however they do not stop crawlers but from users it is irritating to them. Isn't it?

"Broken" links are a natural occurence of the Internet, from time to time.

If they are on your site fix them, if they are not don't worry about it.

Nothing "bad" will happen just because some links are returning a 404 error.

Originally Posted by chrishirst

BTW

If you want to see what bots see, download WebBog and look at some pages.

google webmaster tool has the same tool enables you to do the same. lol