By Olivier Duffez
Google test: hyphen and underscore
November 2004
The best word separators for Search Engine Optimization
Does Google see underscores "_" and hyphens "-" as dividers ?
The answer is: Google sees hyphens as dividers in URLs and body text, and ignores underscores (underscore is not considered as a divider by Google).
Below are the tests we made:
Google Test 1 : Underscores or hyphens as dividers in URL The following URL: wagatukepo-sitynozfau-mazidipole_vukertalet.php contains 4 keywords separated by hyphens or underscores. Before we started our test we did search Google for each of these keywords: wagatukepo, sitynozfau, mazidipole and vukertalet and there were no Google results. Few days later once Google indexed our new URL we did the same search for each of these keywords.
Results: wagatukepo: 1 Google result sitynozfau: 1 Google result
mazidipole: No Google result vukertalet: No Google result
mazidipole_vukertalet: 1 Google result
Conclusion: Google sees hyphens as dividers in URLs and ignores underscores
Google Test 2 : Underscores or hyphens as dividers in Body text In wagatukepo-sitynozfau-mazidipole_vukertalet.php we did type keywords: bozaketerp-boujulanbi et vorismetapalu_terplamili As for Google test 1, we did search Google for each of these keywords: bozaketerp, boujulanbi, vorismetapalu and terplamili and there were no Google results. Few days later once Google indexed our new URL we did the same search for each of these keywords.
Results: bozaketerp: 1 Google result boujulanbi: 1 Google result
vorismetapalu: No Google result terplamili: No Google result
vorismetapalu_terplamili: 1 google result
Conclusion: Google sees hyphens as dividers in Body text and ignores underscores (underscore is not considered as a divider by Google)
Our test confirms what GoogleGuy said in WebmasterWorld:
Yah, I'd stick to hyphens, periods, or commas. Most people seem to prefer hyphens. If you use an underscore '_' character, then Google will combine the two words on either side into one word. So bla.com/kw1_kw2.html wouldn't show up by itself for kw1 or kw2. You'd have to search for kw1_kw2 as a query term to bring up that page.
Related articles and tools we have used for this test
- Ranking report is generated by Agent Web Ranking
- Should You Use Targeted Keywords in URL?
- Robotstats is a free application analysing the web robots on your site
About the Author
Olivier Duffez is an SEO consultant specialized on Google. Working on the Internet since 1997, he created in 2002 Web Rank Info, a free SEO resources French community (+230,000 members), and in 2003 his company Web Rank Expert.
He's giving SEO conferences in Ranking Metrics and wrote a book about Google and SEO in 2004.