Google has launched validator.ampproject.org, which is a new tool to validate AMP pages. It provides a simple web UI for the AMP Validator. There is a Chrome Extension as well.
You need to provide a URL to load the AMP HTML source code from, or copy/paste .the source code, editor will display validation messages between the lines. The tool is open source, so you can file bugs, send fixes and tweak.
Ritu from PageTraffic is a qualified Google Ads Professional and Content Head at PageTraffic. She has been the spear head for many successful Search Marketing Campaigns and currently oversees Content Marketing operations of PageTraffic in India.