Anonymous pull limits on Docker Hub decreased by 1 for every 2 manifest GETs. The window was also different from the official 6 hours.

When estimating whether a CI that pulls anonymously will reach Docker Hub's limit of "100 pulls per 6 hours," the answer ...
InfoWorld

JFrog devops users freed from Docker Hub image-pull limits

JFrog has partnered with Docker to exempt cloud-based JFrog Devops Platform users from Docker Hub image-pull rate limits. The first milestone of the arrangement gives developers using the JFrog ...