If you spot an inaccuracy in this table, please let us know .
NixCI reads your
flake.nix
and automatically discovers what to build.
All
configuration
is optional.
If it builds with
nix flake check
locally, it builds on NixCI.
Hydra requires configuring jobsets through its web interface or declarative project specifications. It does not support Nix flakes.
NixCI automatically discovers all flake outputs and creates build jobs for them.
Hydra does not support flakes.
NixCI uses standard Nix flakes. Your build definition is your flake.nix, which works everywhere Nix does.
Hydra uses Nix, but requires a Hydra-specific jobset configuration.
NixCI has built-in support for continuous deployment and impure tests with access to secrets and the network.
Hydra is focused on building derivations. It does not have built-in support for impure tests or deployment.
NixCI automatically runs deployment after all builds and tests pass, with no manual dependency declaration needed.
NixCI's hosted workers have 16 vCPUs and 64 GB of RAM, billed per second of actual build time. You can also bring your own workers with whatever hardware you choose.
Hydra has no hosted offering. You must provision and maintain your own build machines.
NixCI has built-in Cachix support. Just add your Cachix cache name to your configuration.
NixCI caches automatically without any configuration. Every build result is cached and subsequent builds pull from the cache to skip work that's already been done.
Hydra has built-in binary caching and serves as the source for cache.nixos.org.
NixCI can push build results to your own binary cache via SSH.
Every job on NixCI can be reproduced locally with a single command. NixCI shows you the exact command for each job, so when CI fails, you can start fixing it immediately on your machine.
Hydra provides a shell script to reproduce each build locally.
NixCI provides the exact command to reproduce each job locally, including for impure tests and deployments.
NixCI works with GitHub , GitLab , and Codeberg . One CI system across all your forges.
NixCI supports self-hosted GitHub Enterprise instances.
NixCI integrates with GitLab.com via webhooks and commit status updates.
NixCI supports self-hosted GitLab instances.
NixCI integrates with Codeberg.org via webhooks and commit status updates.
NixCI supports self-hosted Forgejo instances.
A single NixCI installation can serve GitHub, GitLab, and Codeberg repositories simultaneously.
NixCI can be fully self-hosted on your own infrastructure, including the leader, workers, and cache. It also works with self-hosted forges like GitLab and Forgejo.
Hydra is fully self-hostable and is the only deployment option.
NixCI does not have FlakeHub integration. FlakeHub only allows publishing from trusted platforms .