Backlinks are very important in SEO because the entire off-page SEO activity is based on it. Therefore, you should know how many backlinks your competitor’s website has.
There are a lot of paid tools but there are very few free tools which show complete backlinks.
Backlinkwatch
I use this tool a lot because it is very fast and absolutely free. It shows you maximum 1000 backlinks and Many people use this tool.
It also shows anchor text and also shows which link is dofollow and which is nofollow.
That means it is giving you paid like service for free and that too for many years.
Semrush
If you sign up on Samrush then you can check backlinks of 10 websites daily. It will show you maximum 50 backlinks in your free account.
Backlink-tool.org
This tool is also free and in it you can check backlinks of 3 websites in a day. It does not show complete backlinks but the backlinks it shows are quality backlinks and they are shown rating wise.
I also felt like it filtered out low quality backlinks. If it really does then you should use this tool.
TheHoth
It is also a good tool But its report is taken from Samrush.
You will get to see complete backlinks only when you download the report, otherwise only sample report will be available in the web panel.
I did not get to see complete backlinks in this and it is giving only a semrush free account report.