Spellist offers a service, for free, that is very useful: spell checking your website. You just go to their site, put in your web page’s URL, and it gives an analysis of the page. It lists how many spelling errors it found and then which words were found to be wrong. This includes meta tags and descriptions.
It’s a great and useful service, but has some flaws. It doesn’t handle contractions very well, calling the part of the word before the apostrophe and after it as two words that are wrong. Otherwise, it did a good job.
I tested it with several web pages on a handful of sites and then copy and pasted the text from those sites into Microsoft Word. Comparing the results, Word found fewer errors, but the errors found that were legitimate (not contractions or proper names) were the same. So the dictionary Spellist.com uses is at least as good as Microsoft’s.
Overall, this is a useful (and free) website. So it’s worth utilizing while it’s there.