Hello everyone Lately I've been trying out all sorts of rank checkers to see which one is the most accurate. I've been watching 3 keywords very closely for nearly a month now. Google updates the SERP positions over about 4 days across its data centers, so you don't get an accurate view until you weigh up the weekly average. When viewing any real time result, you could be looking at an old result, or a new update. I have compared - serpbook seocentro seo powersuite rank tracker webmaster tools freeproxyserver.ca (I just search Google myself) wordpress rank tracker plugin, by Peter Coughlin (I haven't got around to testing serpbuddy or anymore tools. If any of the owners want to PM me and join the test feel free.) My conclusion? Every single one is different! None of them match up. Webmaster tools is by far the worst! Doesn't even come close to being right. Wordpress rank tracker plugin is accurate, if it manages to update (maybe only once a week) I don't recommend installing this, especially if you already have analytics installed. seocentro is actually very good, and free! It somehow appears to be 24-48hours ahead of serpbook. Is seocentro flawed? Yes... when using endless amounts of free proxy servers, the SERP results never match back the same... According to seocentro I have the top 3 spots in Google. Its been saying that for 2 weeks now. But no matter how hard I check, I can only ever see myself in #1 but no #2 + #3 also. Their results are different every single day/hour, so you cant say they cache their results either. I'd like this one explained... For the same keyword Google Webmaster tools says I'm in #37 for the last month. Couldn't be more wrong... why bother making the tool Google, if your not going to show true results? If anyone should know the SERP positions then its you guys. The SEO powersuite rank tracker shows number one, but it's quite awkward to use, gets blocked alot, and is not worth the money. Doesn't give me a full view of the rankings. The results do match up with seocentro though, and the free proxy servers. I've been doing this comparison for a month now, and trying to watch only stable keywords. I clear my browser, US private IPs etc when needs be. I recommend people only check their keywords once a week and view their average position. I believe services like serpbook + serpbuddy etc are very good for this, because they can show you the average positions for the week. Checking your SERP's daily will confuse you, especially if your doing SEO and trying to gauge what service is effective. Just don't bother looking at daily results, because you do not know what your viewing. My current method now is seocentro, serpbook, and free proxy servers every few days and try to gauge my weekly average. I believe it's the only honest way to view your SERP positions. Hope the info helps some of yous, feel free to post any comparisons of your own!