61 SEO Ranking Factors

1. Keyword in URL page name:(Google patent) Order of keywords is important. First word is most prominent, etc.

1. Keyword in domain name:  Same as above
2. Keyword in page title:  The keyword that is closest to the beginning is the most important. For best results, the title tag should be 10 to 60 characters and have no special characters.
3. Keyword in description meta tag: Search engines used to rely on this tag pretty heavily, but do not do so any longer because of spammer abuse. This tag will help users find content in search results however. Sometimes search engines will use it, sometimes they wont. For best results, the description should be less than 160 characters.
4. Keyword in keyword meta tag: Search engines (it doesn't seem like Google uses it at all) hardly ever use this tag for ranking results. It can help the search engine determine content theme, however. The keyword should be on the page somewhere and shouldn't appear more than twice. If this is not done content will be penalized for irrelevance.
5. Keyword density in body text: For best results the density (all keywords within phrase/total words on page) should be between 5 - 20%. Care must be taken to avoid to high of a density. The density rate at which search engines consider content spam depends on the topic. It is better to be safe than sorry and remain on the side of caution.
6. Individual keyword density: For best results the density (keyword/total words on page) should be between 1 to 6%. Care must be taken to avoid to high of a density. The density rate at which search engines consider content spam depends on the topic. It is better to be safe than sorry and remain on the side of caution.
7. Keyword in H1, H2,….. Hx: Use Hx tags when possible, but don't overdo it. Include the keyword in these tags. This is an important factor.
8. Keyword font size/style: Bold and italic font styles on the keywords are considered more important than other words on the page. (This is according to a Matt Cutts blog entry from July 2006)
9. Keyword proximity when phrase contains more than one keyword: Words that are directly adjacent are considered more related.
10. Keyword phrase order:It is important that word order on the page matches the word order of the search term. For example, if a common search term is chromatography columns, then the word order on the page should be chromatography columns, not column chromatography.
11. Keyword prominence: How close to the top of the page does the word appear? The earlier the better.
12. Keyword in alt text: The alt tag should describe photo and when possible it should have the keyword.
13. Keywords in links to site pages (title tags on links): If there are links to other pages on the site, anchor text should be used to describe the link. When possible this link should contain the keyword.
14. Keyword in internal links (keyword within link text): Link should contain keyword. The file that the link is pointing to should have the keyword(s) and multiple keywords should be separated by hyphens.
15. Navigation structure: How deep are the pages in the web site content? For best results, it should only take 2 clicks/at most 4 clicks to go to any page from the main navigation.
16. Contextual / intra-site links: Contextual links should be used appropriately. For example, if a page is talking about formulation but mentions chromatography, then the word chromatography can link to the chromatography section for more information.
17. Keywords in outgoing links/quality of outgoing links: Recent Google patent. Only link to web sites with good reputation. If you don't want the link to count as a vote for the external sites content, use no-follow tags.
18. Outgoing links: should be checked periodically to make sure they are still active. Broken links can harm SERPs. Do not link to link farms.
19. Outgoing link anchor text: Should be on topic and descriptive. When possible they should include the keyword/keyword phrase.
20. Link stability over time Google patent: Outgoing links shouldn't change frequently.Frequently changing links are considered "Link Churn."
21. External link: validation Are outgoing links still valid?
22. Less than 100 links out total: Google recommends that a web site have no more than 100 outgoing links, but this number depends on the web site size.
23. Domain name extension:????????????? Check
24. Page file size: For best results, pages should be under 100K. Files smaller than 40K is preferred. The reason for this is that larger pages require more search engine resources and search engines prefer to crawl pages that take as little time as possible.
25. Hyphens in URL: Hyphens are the preferred method of separating words in a URL. For best results only one or two should be used. If there are more than four or more, search engines think it looks like spam.
26. Freshness of pages Google patent: Google and other search engines like content on pages to change frequently over time. Pages that have fresh content get placed higher than those that remain the same.
27. Freshness of overall content Content: This is a measure of the ratio between fresh content and oldcontent. The more new pages/content the better.
28. Freshness of links Google patent: For highly trusted sites this is a good thing, but for new sites and low trust sites it's a bad thing.
29. Frequency of updates: The more frequently pages are updated, the more frequently the pages will get spidered by the search engine. The more content gets spidered, the newer the content will be in the search engines cache.
30. Page theming: Do pages on the entire web site or web site sections exhibit a consistent theme? Are there a lot of pages within a section that have this theme? If there are more pages with content on a consistent topic those pages will rank better when searches are made for that topic. 
31. Keyword stemming: For example, stem, stems, stemmed, stemmer, stemming, stemmist, and stemification.
32. Semantics: Synonyms and related terms are beneficial.
33. URL length: Try to keep URL length short. For best results use less than 100 characters. 
34. Site size: Google and other search engine usually prefer content from larger web sites. Exceptions to this would be web sites with computer generated pages. 
35. Site age Google patent: Old sites are considered more trustworthy than newer sites. 
36. Age of page vs. age of site: Newer pages on older sites will get faster recognition than newer pages on newer sites.
37. Text presented in graphics form: Pages that only have text presented in graphic form do not perform well in search results. Most of the time they don't even get indexed. 
38. Affiliate sites: Sites with affiliate content are treated negatively by search engines. The content on affiliate sites is usually identical with very little unique content.
39. Over optimization penalty (OOP): Penalty for over-compliance with generally accepted optimization practices. Also includes things like the keyword to content ratio being too high and over use of H1 tags. 
40. Links to low trust/banned sites: Check Google's status on all sites you link to. Not only when the link is first made, but also periodically. Remove all links to web sites that have lost good status with Google.
41. Redirect thru refresh meta tags: Refresh meta tags are generally considered negatively by search engines. When ever possible there use should be avoided.
42. Banned/bad words: Do not use words search engines consider bad.
43. Poison words: Some words are used frequently in spam and poor content. For example, having the word "Click here" and "Links to" in content could make the page place lower. Do not use phrases that are associated with spamming (Google patent). 
44. Over linking between sites: Excessive linking between a few sites, especially between sites from the same web host/similar IP addresses, is viewed negatively by most search engines. Search engines consider this type of linking an attempt to trick the search engine. According to Matt Cutts this doesn't apply to a small number of sites. 
45. Copying copyright protected imagery and text from other domains If reported: Google will give strong penalties.
46. Keyword stuffing threshold: Excessive keyword repetition in body and various tags will result in demotion. 
47. Keyword dilution: Including too many unrelated terms in your content reduce the strength of your content theme. The topic should focus on specific keywords/phrases and not include unrelated information. 
48. Consistency in page edits: Google patent. When page content is changed, does it contain information about the old topic? If the theme changes frequently, Google may reduce it's SERP.
49. Changing content to often: Google patent. Changing content is usually a good thing, but if it is changed to often it can be a bad thing. Changes should be done in a consistent manner. If Google thinks the change is done only to improve SERP, the content will be penalized. 
50. Anchor tag changes: Anchor tags shouldn't be changed frequently.
51. Dynamic pages: Dynamic pages aren't search engine friendly. Search engines do better when there are only a few variables. For best results, pages should have at least some hard coded links and no more than 2 or 3 variables.
52. To much Java script: Search engines don't like Java script. If Javascript is used, it should be called from an external file.
53. Flash Search engines: have a hard time indexing flash. If it is important for a page to perform well in search results, it is better to have HTML content. If flash is needed, provide an HTML alternative.
54. Frames: Spider bots have trouble indexing frames. 
55. "No index" tag: This tag is used to keep the search engine from indexing a page. Do not use for pages that you want the search engine to index.
56. Single pixel links: Creating a single pixel link is seen as an attempt to hide a link. Google advises against any attempts to hide content or links.
57. Invisible (cloaking) text: Invisible text is text that is intentionally hidden from view. This could be done in a variety of ways, including making the text color the same color as the background. Cloaked text can't be seen by web site visitors, but it can be seen spiders. Since this is seen as an attempt to manipulate SERP, this is penalized by search engines.
58. Gateway/doorway pages: ??????????????
59. Duplicate content: Google doesn't penalize for this, but it will only display one version of the content in search results. Usually the oldest content is chosen when ranking results. 
60. Site Speed: Google’s next ranking factor. 
61. Review: Whole website once