What are some alternatives?
When comparing OpenGraphTool.com and Open Site Explorer, you can also consider the following products
OpenGraphTags - Open Graph Tag Simulator
Majestic - Majestic - Link intelligence tools for SEO and Internet PR and Marketing. Site Explorer shows inbound link and site summary data.
MetaTagsTool.com - Meta Tag Analyzer, Simulator, & Generator
Screaming Frog - Screaming Frog is search engine marketing agency offering search engine optimisation and pay-per-click advertising services.
MetaTagTools.com - Meta Tag Analyzer and Generator
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.