Its free features are:
On-page SEO report
Redirect tracer with HTTP Headers
Broken link checker
In addition, as an Ahrefs user, you get:
SEO metrics for every site and page you visit, and for Google search results
Keyword metrics, such as search volume and keyword difficulty, directly in SERP
SERP results export
Analyze the on-page elements for any page and find potential issues with one click.
Title and description
Indexability and crawlability
Content subheaders (H1-H6) and hierarchy
Social tags (OG and Twitter Cards)
Published and updated dates
For JS-powered websites, the toolbar will compare the raw HTML vs. rendered titles and meta descriptions to show you any differences.
For redirecting URLs, Ahrefs SEO Toolbar shows you the full redirect chain that leads to the destination page.
It also shows the HTTP headers of any URL.
Find all outbound links on a page in one click. Internal, external, followed, and nofollowed links are highlighted in different colors for easy evaluation of link opportunities.
Audit your pages for broken links and find broken link opportunities on resource/links pages in your niche. Dead outbound links are highlighted red, and you can export to a CSV in one click.
Instantly see important SEO metrics for each page and website you visit:
Domain Rating (DR)
URL Rating (UR)
Ahrefs Rank (AR)
Number of backlinks
Number of referring domains
Estimated organic search traffic
Number of keyword rankings
Get a better sense of ranking difficulty and competition with SEO metrics for the top-ranking pages. Export metrics for the top 100 results in one click.
Use inline metrics to assess the potential of any keyword opportunity without leaving the SERP.
Ahrefs SEO Toolbar will show you:
Search volume (both global and country-specific);
Keyword Difficulty (KD);
Cost per Click (CPC).
Install Ahrefs' SEO Toolbar and have the most important SEO information at your fingertips at all times.