Open Educational Resources (OER) provide learning opportunities for all. Usually, OER and links to OER are curated in Repositories of OER (ROER) for open access and use by anyone, including people with disabilities, at any place at any time. This study analyzes the reputation/ authoritativeness, usage, and accessibility of thirteen popular ROER for teaching and learning using three Web Analytics and five Web Accessibility tools. A high difference among the ROER was observed in almost every metric. Millions of users visit some of these ROER every month and on average stay 2–26 min per visit and view 1.1–8.5 pages per visit. Although in many ROER most of their visitors come from the country where the ROER hosting institute operates, other ROER (such as DOER, MIT OCW, and OpenLearn) have managed to attract visitors from all over the world. In some ROER, their visitors come directly to their website while in a few other ROER visitors are coming after visiting a search engine. Although most ROER are accessible by users with disabilities, the Web Accessibility tools revealed several errors in few ROER. In most ROER, less than one third of the traffic is coming from mobile devices although almost everyone has a mobile phone nowadays. Finally, the study makes suggestions to ROER administrators such as interconnecting their ROER, collaborating, exchanging good practices (such as Commons and MIT OCW), improving their website accessibility and mobile-optimized design, as well as promoting their ROER to libraries, educational institutes, and organizations.