There are thousands of different tools on how to improve a website or some parameters of it, some who analyze technical aspects, other than analyzing the seo and social that is your website and others that help you improve your design.
SEO Tools for Web Developers
These tools can show you things that failures or improve your website that you had not stopped to think, like a thousand validation errors, meta-tags shoddy or white, right or wrong that fits your website to different sizes screen popularity in social networks … and Sunday I bring a handful to have nothing better to do (and free).
Woorank is a comprehensive service that in its free version rate considering your website 120 + values (traffic estimate, indexed pages, backlinks , meta-tags, seo , response time … well, what is complete).
I use this service for a few months, the first time I used it I looked at a lot of things to improve seo (and I’ve improved since you also explain how) and are basic things that not stop to think about them.
The service GTMetrix is a comprehensive seo analysis of the efficiency of your website speed issue. It is keen in assessing various factors and rating their importance as if it were an appliance ( A perfect and if F if greatly affects the speed of your website) .
The tool Simply testable by sitemap.xml scans all your web pages in search of validation errors, missing attributes alt , file existence robots.txt and a few other things. The advantage of this tool is that at most one page scans for errors (and after trying today … I think I’m going to play a little work).
Simply Testable’s sample test for Blog Helpline
ScreenQueries is a tool that shows the site we choose in different screen sizes and proportions, perfect for testing our Responsive Designs comfortably, besides giving us the ability to use mobile and tablet sizes preset. Esra tool works with <iframe> therefore can display a page directly from localhost and it will be found more useful when creating an adaptive design.
Screaming Frog SEO Spider Tool
This tool is not online, but has version for Windows , Mac and Linux and analyzes the seo of entire site, page by page, picture by picture and letter by letter.
It gives us all the information on each page, as the description length, number of titles ( H1 , H2 …) links that each page, information about images etc.
Last few words…
You may heard of many better seo tools apart from this list, but I have selected a few with slightly different features, which certainly works great in improving our website in-design. But I recommend that if you have never used a tool of these do not panic, things are improving in everywhere (but slowly improving ) and I hope that you may find helpful.