Hey everyone! 
When refactoring Nextflow pipelines or testing bug fixes, it’s often difficult to verify whether output files, execution metrics, or trace reports changed and by how much. I’ve been working on nf-diff, a dedicated Nextflow plugin that compares the output directory structure, metrics, process relationships and generated artifacts between two Nextflow runs. It helps you quickly spot unintended data drift, missing files, or unexpected changes across runs. 
What nf-diff gives you:
- Direct comparison of output directories and execution artifacts generated by Nextflow.
- Clear visual summaries of added, modified, or removed outputs and trace data.
- Lightweight CLI integration for local testing or custom pipelines.
It supports many features and multiple output formats. I’m attaching the HTML report of a nf-diff I did here to showcase the plugin capabilities 
report.html (178.9 KB)
Bonus — Use it in CI:
I’ve also built the nf-diff GitHub Action so you can run these output comparisons automatically on Pull Requests and see the results directly as PR comments!
Official website:** nf-diff | nf-diff
Core Project: GitHub - mribeirodantas/nf-diff: Nextflow plugin to compare runs · GitHub
GitHub Action Demo & Live PR Examples: Pull requests · mribeirodantas/demo-nf-pipeline · GitHub
Give it a spin, star the repo if you find it useful, and let me know if you have any feedback or edge cases to test! Open to contributions! 