Proton Mail

Proton Mail ranks 401st overall in the SaaS category with a composite score of 41 out of 100. The score summarises how the organization presents itself to developers across GitHub, its documentation, its packages and the wider community.

Its code quality and shipping velocity come across as solid, and are what most developers will notice first when they land on the organization. By contrast, its developer experience and AI and agent readiness look minimal today, which is the clearest area where a small amount of focused work would visibly move the needle. Taken together, the picture is of a company whose public developer surface is neither uniformly polished nor uniformly weak, and where different audiences (contributors, integrators, evaluators) will likely form very different first impressions depending on which door they walk through.

Proton Mail maintains 186 public repositories on GitHub, built primarily in TypeScript, Kotlin and Swift, which together have collected 16,265 stars and drawn contributions from 20 developers outside the core team, 19 of those repositories have seen commits in the last 90 days, a useful proxy for how much of the codebase is genuinely alive rather than archived.

For anyone evaluating Proton Mail as a technology choice, weighing a contribution, integrating the APIs, or comparing it against similar companies in the space, the sections below break down each of these signals in detail and link straight through to the underlying repositories, documentation and community threads that inform the score.