How to find bad link

Hi,
I am trying to ranking my site about 4 month but no improvement.so now i want to find out my website bad link.Bet i have no idea how to find bad link.Please help me and give me right suggestion.

There are many website which provide free back-links details. You can find these back-link of your website, after that check every back-link website PR, IP Address, Single page website and Spamming website. And if you find that back-link is poor quality, then send them a mail for removing purpose.

Regards
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Can you give me one website name That will be best for back link checker.

Aside from using free tools, you can also check google webmaster tools for some warning on your sitemap.

I would like to suggest Remove’em to know how many links towards your website are really suspicious. To get link data you have to subscribed with them. But it is trustworthy and effective.

In regards to your question and opening post, you might want to check the following sites for detailed instructions:

http://www.wikihow.com/Identify-Broken-Links-in-Your-Website-Using-Google-Webmaster-Tools

The sites indicated above give a some guidance and detailed information on different ways on detecting “bad” links. Just as other have already stated it would be wise to create an account with Google Webmaster Tools and Bing Webmaster Tools. Both are free and can help analyze your links to give you a better understanding on where your site stands.

To find bad links use ahrefs, opensiteexplorer and webmaster tool. You have to check backlinks which are providing huge backlinks and those links which looks paid and not follow the Google quality guidelines.

You can check out your spam or bad links through Google Disavow tools and then remove them individually for better ranking of your website in Google and other search engines.

I don’t thing there is any tool which can find BAD links, you have to do it manually. thanks