Does it matter how long or short your web pages and blog posts are vis-à-vis your search engine rankings? Sometimes it does and sometimes it doesn’t: it depends on your competition. I have seen blank web pages — with just the title carrying the expression searched for — appearing at the first spot on Google, but they are extreme cases.
So ideally how long should be your web pages and blog posts?
As long as it is required to convey your message. Normally, it is good to have between 200-300 words and this may or may not include your headings. Actually longer pages allow you to include elements that increase your search engine rankings for particular search expressions.
For example, if you have say, 4 paragraphs, you can use at least to headings to highlight the main points using your keywords. Then in one of the paragraphs or sections you can use an HTML list to explain yourself ,as words used in bullets are taken seriously by the search engines.
A longer page also shows that you’ve got much to say about your subject. Just make sure you really have something relevant to say. This implies that don’t create every page for the purpose of SEO (there is nothing wrong in that if you’ve got plenty to write); always remember that you are eventually creating your web pages and blog posts for human readers and getting good search engine traffic for them is an added bonus. If you can convey a message in just two sentences, write just two sentences.