Embodiments seek to improve prefetch hinting by using automated browsing clusters to generate and update hinting models used for machine-generated hints. For example, hinting machines can include browsing clusters that autonomously fetch web pages in response to update triggers (e.g., client web page requests, scheduled web crawling, etc.) and generate timing and/or other hinting-related feedback relating to which resources were used to load the fetched web pages. The hinting machines can use the hinting feedback to generate and/or update hinting models, which can be used for machine-generation of hints. Some embodiments can provide preliminary hinting functionality in response to client hinting requests, for example, when hinting models for a requested page are insufficient (e.g., unavailable, outdated, etc.). For example, without having a sufficient hinting model in place, the hinting machine can fetch the page to generate preliminary hinting feedback, which it can use to machine-generate preliminary hints.